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Hi Viz Green
Hi Viz Green

This product is no longer available, but don't go just yet.


  • Adjustable AirStretch belt features ample stretch and chafe-free edging for comfort while maintaining bounce-free performance
  • Back-friendly symmetrical design eliminates uneven weighting, chafing and uncomfortable pressure points
  • AirFlow Mesh™ hybrid mesh technology wicks away moisture and circulates air between your back and the pack
  • 40 cu. in. compartment holds key, ID and cash
  • BPA-free 20 fl. oz. Hydraform™ water bottle nests laterally for a naturally comfortable fit
  • Low-profile bottle flattens center of gravity, reducing slosh and bounce
  • The Amphipod Full-Tilt AirStretch Velocity hydration waistpack securely holds its bottle in place and accommodates easy bottle access


View all Amphipod Hydration Waistpacks

REI membership


Best Use Running
Gear Capacity (L) 0.65 liter
Gear Capacity (cu. in.) 40 cubic inches
Liquid Capacity (L) 0.59 liter
Liquid Capacity (fl. oz.) 20 fluid ounces
Weight 8.5 ounces
Weight - Metric 0.24 kilograms
Fits Waist/Hips 21 - 48 inches
Material(s) Nylon/polyester
Pack Access Top
Number of Exterior Pockets 1 main compartment
Dimensions 10 x 5 x 3 inches
Gender Unisex

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REI's guarantee doesn't cover ordinary wear and tear or damage caused by improper use or accidents.

If your item has a manufacturing defect in its materials or workmanship, you can return it at any time. See our limited warranty.

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*10% is typical but not guaranteed. Your refund is based on eligible purchases, which exclude REI gift cards, services, fees, REI Adventures trips, REI Garage, and discounted items. Learn more