
On
Ultra 5l Hydration Jacket Removable Pocket
The On Ultra 5L Hydration Jacket with Removable Pocket is a lightweight 5-liter hydration vest designed for trail running over short and medium distances. It includes two 500 ml Hydrapak soft flasks, features stretch mesh fabric, an adjustable chest fit system, a large removable zip pocket, front and back storage pockets, and reflective details for low-light visibility. The vest packs into its own small carry pouch for transport.
- Gender
- unisex
- Style
- technical, performance
- Category
- Sporting Goods > Outdoor Recreation > Hydration Systems
Specifications
Ultra-light 5L trail-running hydration jacket with removable pocket and two 500ml flasks.
Ultra-comfortable stretch mesh fabric, toggle fit-adjustment system, reflective details, packs into carry pouch.
- Material
- Front: 100% recycled polyester; Back: 85% recycled polyamide, 15% spandex; Pockets: 85% recycled polyester, 15% spandex; Bag: 100% recycled polyamide; Water bottle: 65% thermoplastic polyurethane, 21.5% polypropylene, 10.1% silicone, 3.4% polyoxymethylene
- Style
- technical, performance
- Gender
- unisex
- Age Group
- adult
- Condition
- new
- Category
- Sporting Goods > Outdoor Recreation > Hydration Systems
Additional Attributes
- ultra-light 5 litre trail-running accessory
- includes two 500 ml Hydrapak flasks
- ultra-comfortable stretch mesh fabric
- toggle fit-adjustment system on chest
- large removable zip pocket
- front and back pockets
- reflective details for visibility in dark
- packs into small carry pouch
Product Insights
The On Ultra 5l Hydration Jacket Removable Pocket is the lightest 5L hydration vest at 127 grams, designed to minimize bounce via an adjustable hem, bungee retention, and foam padding. Its modular core is a removable, water-resistant, sweatproof dry pocket that compresses to hand-sized, allowing the vest to function as a stripped-down harness or standalone pouch. Stability is maintained by non-stretch pockets and bungee loops, while internal foam cushions the chest against flask caps. The vest integrates a whistle, first-aid guide, and daisy chain loops for accessories, and accepts standard Hydrapak flasks. Made from 85% recycled polyamide, it offers quick-access gel pockets and a trash pocket, balancing ultra-light portability with the tradeoff of minimizing storage when the pocket is detached.
Verified claims
- Bounce reduction
- Adjustable hem, bungee retention, lightweight 127 g chassis, and foam padding combine to reduce bounce.
- Weight
- Lightest 5L hydration vest at 127 grams.
- Packability
- Compresses to hand-sized; removable pocket adds dry storage.
- Stability
- Non-stretch pockets and bungee loops prevent bottle bounce at 127g.
- Water resistance
- Removable pocket is water-resistant and sweatproof.
- Built-in features
- Integrated whistle, first-aid guide, and daisy chain loops.
- Configurations
- Removable pocket detaches for stripped-down harness or standalone dry pouch.
- Front pocket layout
- Quick-access gel pockets, a trash pocket, and an integrated safety whistle.
- Removable dry pocket
- The large removable zip pocket is a water-resistant dry bag with taped seams.
- Portability
- At 127g, it is the lightest in its class and compresses to a hand-sized pouch.
- Modularity
- Removable dry pocket adds 10L vest functionality; daisy chains accept poles and accessories.
- Value
- 85% recycled polyamide main body in a 127g vest at a sale price of $99.95 CAD
- Cushioning
- Internal foam pads behind each flask cushion the chest and prevent bruising.
- Pocket features
- Removable dry bag and trash pocket keep layers dry and irritation-free.
- Design features
- Combines the 10L's removable dry bag with anti-bounce stability, weighing 127 g.
- Versatility
- Packs down to hand-sized pouch with flasks; attaches poles; accepts standard Hydrapak flasks.
- Safety
- Integrated whistle and emergency first-aid guide.
- Flask interchange
- Flasks are replaceable with other Hydrapak-compatible soft flasks.
- Comfort padding
- Internal foam padding cushions ribcage against flask caps.
- Storage layout
- Front quick-access pockets hold multiple gels, a phone, and keys, while the back single pocket fits a light jacket.
- Included accessories
- Includes 500 ml Hydrapak soft flasks and a large removable zip pocket.
- Cleaning
- Hand wash cold with mild detergent or use a gentle machine cycle in a laundry bag; avoid fabric softeners, bleach, and high heat, and air dry away from direct sunlight.
Product record
- Title
- Ultra 5l Hydration Jacket Removable Pocket
- Brand
- On
- Price
- 260 CAD
- Availability
- Out of stock
Image Analysis
3 images- 01

Product
Front-facing black running hydration vest with two front soft-flask pockets, visible soft flasks with translucent caps, mesh back panel, multiple adjustable cord toggles, and a vertical zip pocket on the left front pocket.
- Overall shapeSleeveless vest laid flat showing the front side with two wide padded front panels separated by a central mesh back panel and a straight lower hem.
- Mesh back panelCentral back area made from a tightly woven black mesh fabric covering the torso area between the two front panels.
1 region
x 0.36 · y 0.17 · w 0.28 · h 0.66 (high) - Left front pocketLeft front pocket of soft woven fabric with an external vertical zipper pocket and an upper opening holding a translucent soft flask.
1 region
x 0.07 · y 0.30 · w 0.37 · h 0.55 (high) - Left pocket zipperVertical water-resistant zipper with a small fabric pull located on the outer face of the left front pocket.
1 region
x 0.13 · y 0.48 · w 0.08 · h 0.18 (high) - Right front pocketRight front pocket of the same soft woven fabric, with a wide upper opening holding a translucent soft flask and a large reflective stylistic 'on' logo printed vertically.
1 region
x 0.53 · y 0.32 · w 0.40 · h 0.56 (high) - Brand mark on right pocket“Lower-case stylized 'on' logo printed in a light reflective color on the outer face of the right front pocket.”
1 region
x 0.70 · y 0.47 · w 0.16 · h 0.20 (high) - Soft flasksTwo translucent soft flasks inserted into the upper openings of the front pockets; each flask has a frosted, push-pull style cap and a short neck.
2 regions
x 0.15 · y 0.08 · w 0.18 · h 0.22 (high); x 0.67 · y 0.08 · w 0.18 · h 0.22 (high) - Adjustable cord systemMultiple bungee cords with small plastic cord locks and toggles running horizontally across the front panels and at the shoulders and sides for fit adjustment.
1 region
x 0.27 · y 0.42 · w 0.46 · h 0.38 (high) - Top shoulder loopsThin cord loops with plastic end toggles visible at the top of each shoulder panel.
2 regions
x 0.19 · y 0.00 · w 0.12 · h 0.13 (high); x 0.69 · y 0.00 · w 0.12 · h 0.13 (high) - Inner center labelSmall rectangular stitched label centered at upper back with multiple lines of fine text and a small circular graphic; text is too small to read at this resolution.Partial
1 region
x 0.43 · y 0.14 · w 0.14 · h 0.10 (medium)
Other
Product photographed flat against a light neutral background with soft even lighting, top-down centered composition, and minor shadowing beneath the vest.
- Shot compositionTop-down centered shot of the vest laid flat showing the full front area; image crops near the shoulder loops but shows entire torso and pockets.
- Background and lightingSmooth light gray background with even diffuse lighting and soft shadows under the lower edge of the vest.
- Image qualityHigh-resolution clear photograph with visible fabric texture and sharp edges; no visible creasing on the background.
Colors
matte black· main fabric (front pockets and panels)#0D0E0Cblack mesh· central mesh back panel#0D0E11frosted white· soft flask capspale reflective gray· logo print on right pocket#BCBCBA- 02

Product
A removable black front pocket attached to a black mesh running vest; features a top horizontal zipper with taped seam, a large vertical light-gray reflective logo on the pouch face, side mesh panels and adjustable drawcords at lower sides.
- Front pouch geometryRectangular soft pouch with a slightly rounded bottom edge and a flat front panel that projects outward from the vest body.
1 region
x 0.18 · y 0.12 · w 0.64 · h 0.48 (high) - Top zipperHorizontal top zipper with a taped seam; zipper pull visible at left top corner of the pouch.
1 region
x 0.18 · y 0.12 · w 0.64 · h 0.06 (high) - Large front logoLarge vertically oriented light-gray circular and arching logo printed on the pouch front, occupying most of the front panel.
1 region
x 0.32 · y 0.24 · w 0.36 · h 0.36 (high) - Small pouch label text“Small uppercase text centered under the logo on the pouch front.”
1 region
x 0.41 · y 0.53 · w 0.18 · h 0.03 (medium) - Left mesh side panelBlack open-knit mesh panel forming the vest shoulder and side area to the left of the pouch.
1 region
x 0.00 · y 0.08 · w 0.28 · h 0.72 (high) - Right mesh side panelBlack open-knit mesh panel forming the vest shoulder and side area to the right of the pouch.
1 region
x 0.72 · y 0.08 · w 0.28 · h 0.72 (high) - Lower central pocket/insertA secondary fabric panel or pocket below the removable pouch, darker black fabric with a straight top edge that tucks under the pouch.
1 region
x 0.28 · y 0.56 · w 0.44 · h 0.24 (high) - Right vertical printed text“Vertical white text printed on the right lower fabric panel beside the lower pocket.”
1 region
x 0.60 · y 0.60 · w 0.10 · h 0.22 (medium) - Adjustable drawcordsPaired thin cord drawstrings with cord locks emerging from lower left and lower right edges of the vest.
2 regions
x 0.00 · y 0.70 · w 0.18 · h 0.26 (high); x 0.82 · y 0.70 · w 0.18 · h 0.26 (high) - Top attachment togglesSmall cord loops with toggle ends visible at the top left and top right corners of the pouch area.
2 regions
x 0.18 · y 0.04 · w 0.12 · h 0.10 (medium); x 0.70 · y 0.04 · w 0.12 · h 0.10 (medium) - Fabric textureFront pouch fabric appears slightly textured with a matte finish; mesh panels have visible diamond-shaped open weave.
- Transcribed small text on pouch“ULTRA VEST PRO”
1 region
x 0.43 · y 0.53 · w 0.14 · h 0.02 (medium) - Transcribed vertical right text“SWISS ENGINEERING”
1 region
x 0.60 · y 0.60 · w 0.10 · h 0.22 (medium)
Other
Studio flat-lay photograph on a neutral light-gray background with even front lighting and soft shadowing beneath the vest edges.
- Shot compositionFlat-lay centered composition showing the front face of the vest and attached pocket, photographed from above.
- BackgroundUniform light-gray background with no props.
- Lighting and shadowEven diffuse lighting with faint soft shadow visible under the lower edge of the vest and pouch.
- Image qualityHigh-resolution image with clear detail and visible fabric texture and mesh weave.
Colors
matte black· front pouch#141414light gray· large logo#C3C3C3black mesh· mesh side panels#0E0E0D- Front pouch geometryRectangular soft pouch with a slightly rounded bottom edge and a flat front panel that projects outward from the vest body.
- 03

Product
A rectangular black removable pocket pouch with a horizontal waterproof-style zipper near the top, two elastic loops with small black toggles at the top corners, a left-side zipper pull with knotted cord, and a large vertical silver reflective 'on' logo centered on the front above small printed model text.
- Overall shapeRectangular soft-sided pouch with a slightly tapered top and a flat bottom edge visible, front-facing view.
1 region
x 0.08 · y 0.14 · w 0.84 · h 0.78 (high) - Main materialTextured ripstop-style nylon fabric with a matte appearance and visible subtle grid texture across the surface.
1 region
x 0.12 · y 0.26 · w 0.76 · h 0.62 (medium) - Top closureHorizontal waterproof-style zipper across the front near the top with a taped seam and visible stitched line below it.
1 region
x 0.08 · y 0.18 · w 0.84 · h 0.08 (high) - Zipper pullLeft-side zipper pull with a short braided cord loop ending in a knotted pair of tails.
1 region
x 0.04 · y 0.20 · w 0.12 · h 0.14 (high) - Top attachment loopsTwo black elastic cord loops at the top corners each terminated with a small rounded black plastic toggle; loops extend above the pouch.
2 regions
x 0.06 · y 0.04 · w 0.12 · h 0.18 (high); x 0.82 · y 0.04 · w 0.12 · h 0.18 (high) - Front logoLarge vertical two-part silver reflective graphic forming the 'on' logo: a circular ring at upper center with a small diagonal rectangle attached, and a rounded inverted U shape below.
1 region
x 0.26 · y 0.28 · w 0.48 · h 0.52 (high) - Model text“Small white printed text centered near the bottom reading ULTRA VEST PRO.”
1 region
x 0.40 · y 0.74 · w 0.20 · h 0.06 (high)
Other
Product photographed flat against a neutral light gray background, centered and hanging so slight shadow is visible beneath; top of image includes the two cord loops and toggles extending into negative space.
- Background and stagingEven light gray studio background with a soft shadow directly beneath the pouch indicating overhead lighting.
- Shot compositionCentered front-facing detail shot showing the full front face of the pouch and top attachments, minimal perspective distortion.
- Image limitationsNo visible packaging, no scale reference, and no hands or props present.
Colors
matte black· main fabric#0E0D0Dreflective silver· logo and small text#BCBABBmatte black trim· zippers and toggles- Overall shapeRectangular soft-sided pouch with a slightly tapered top and a flat bottom edge visible, front-facing view.
Brand PDP Lookup
- Brand
- On
Ultra Vest 10L: Trail Running Vest With Removable Pack