Hydrapak PocketFlask 500ml with Locking Cap

• Low-profile design: specifically shaped for snug running belts and lean vest pockets.
• 500ml capacity: provides standard running-flask capacity in a slimmer format.
• Pinch-welded base: creates a tapered profile that reduces unnecessary bulk.
• Compact 28mm cap: smaller diameter helps make the flask comfortable when carried close to the body.
• Twist-locking cap: opens and closes easily with the thumb and prevents leaks when locked.
• High-flow bite valve: self-seals after drinking to help prevent drips.
• Flexible construction: conforms to the shape of belt and vest pockets.
• Compressible body: shrinks as fluid is consumed and helps reduce water movement.
• Durable TPU: abrasion-resistant construction with RF-welded seams.
• BPA and PVC free.
• Freezer safe: can be frozen and used with contents up to 60°C / 140°F.
• HydraPak Beyond Lifetime Guarantee: covers failures caused by manufacturing or material defects.

The PocketFlask is particularly suited to carrying systems where depth is limited and a conventional flask can feel bulky. Its slim, low-profile shape is designed to sit comfortably in running belts and lean vest pockets.

HydraPak's fit guidance lists the PocketFlask at approximately 230mm × 80mm × 37mm when filled, with suggested pockets around 230–265mm long, 75–100mm wide and 37–50mm deep. Fit should still be checked against the individual belt or vest pocket and its retention system.

The flask compresses as you drink, so excess air can be expelled before use to reduce fluid movement further.

Not sure which bottle or soft flask is right for your vest, belt and hydration setup? See our Running Bottles & Soft Flasks Guide.

If you are unsure about pocket fit, capacity or whether the PocketFlask is suitable for your carrying system, get in touch for straightforward advice.