Back to top

Please select a color/size.


  • Soft material conforms to any pocket making it ideal for a hydration vest, belt or pack pocket
  • Shrinks as you drink, reducing water movement and flask size
  • 42mm cap with adjustable drink tube and removable bite valve; use with or without tube (bite valve can be mounted directly to cap)
  • Can be frozen or filled with hot water (max temp 60°C/140°F)
  • 100% BPA and PVC free
  • Rinse before use; dishwasher safe (top rack recommended)


View all Hydrapak Running Water Bottles

REI membership


Best Use Running
Liquid Capacity (L) 0.45
Liquid Capacity (fl. oz.) 15
Dimensions 6.5 x 2.36 x 1.4 inches
Water Bottle Material Soft Plastic
Material(s) TPU
BPA Free Yes
Bottle Opening Wide
Water Bottle Cap Type Bite Valve
Collapsible Yes
Weight 1.3 ounces
Rated 5 out of 5 by from water on the run Water fountains still haven't been turned on for the spring and summer season, and dehydration during long runs was becoming an issue as temperatures climbed above 40. This bottle is perfect for stuffing into a pocket or running belt to take some water from home, or refill along the way at the usual rest stops.
Date published: 2017-04-21
  • y_2017, m_5, d_25, h_3
  • bvseo_bulk, prod_bvrr, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_1
  • loc_en_US, sid_116543, prod, sort_[SortEntry(order=RELEVANCE, direction=DESCENDING)]
  • clientName_rei-inc
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getReviews, 38ms

Will this fit well in VaporKrar 4L front pockets? The ones that come with the pack leak badly. 

Asked by: Alex
This flask is the same size as the flasks that come with the Nathan VaporKrar 4L Hydration Vest. They will fit in the front pockets.
Answered by: REIservice
Date published: 2017-04-18
  • y_2017, m_5, d_25, h_2CST
  • bvseo_bulk, prod_bvqa, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_1
  • loc_en_US, sid_116543, prod, sort_[SortEntry(order=NUM_ANSWERS, direction=DESCENDING)]
  • clientName_rei-inc
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getContent, 37ms