Size Guide

Ideal for a quick drink on the run. Gobble up a gel, wet a dry throat, or rehydrate. Designed to be used while running, and all of us who can't stay in place!  Stores directly in your front, side, or back pockets. FITLY Flasks shrink as you drink, so nothing ever moves, bounces, or rattles. 

  • No liquid bounce - Soft bite to quick flow
  • Shrinks as you drink
  • Leak-resistant and rigid cap ring for easy refill
  • Light, durable, built to last - 100% BPA & PVC free
  • Ideal to drink on the go

The models to choose from:

  • FLASK150 (5 oz 150ml - 5.5 x 2.75 in): small enough to fit in FITLY's SUB45 front pockets for quick access.
  • FLASK250 (8.5 oz - 250 ml - 7.5 x 3.5 in): when you need a little more.
  • FLASK350 (12 oz 350 ml - 8.75 x 3.5 in): longer flask. Same width as FLASK250. 
  • FLASK400 (13.5 oz  400 ml - 8 x 4 in): go farther, take more.
  • FLASK500-L (17 oz  500 ml - 9 x 2.75 in): the only round bottom flask to load up!
  • FLASK500 (BLADDER) (17 oz 500ml - 8.5 x 6 in): a low profile bladder custom-made to fit the Sub90's thermo-compartment or used as a standalone flask with the screw-on mouthpiece (included). Comes with a 23 in (58 cm) long tube and silicone mouthpiece.  Note: The FLASK500 does not fit the SUB45.
  • FLASK1100 (BLADDER)(37 oz 1100ml - 12 x 6.5 in): an ingeniously low profile custom-made for the Sub180 or used as a standalone super flat soft flask (screw-on mouthpiece included).  Important: The FLASK1100 only fits in the SUB180 and is too big for the SUB90 or SUB45.
  • FLASK1700 (BLADDER) (60 oz 1750ml): our regular larger bladder for all your adventure and day packing.  
  • COMBO = FLASK150 + FLASK250 + FLASK400
  • FLASK Holder + FLASK350: quiver-style holder with a 12 oz flask. Easily adjusts to all adult hand sizes. Stretch pocket for small personal items. Top cinch to secure the flask.  Works with FLASK150-250-350-400.  Does not work any other ones.

How to use:

The mouthpiece or nipple has a soft and hard section. Softly bite the soft part to release the liquid - press on the flask or suck on the goodness!

The more you press, the faster the liquid will exit. The walls collapse as you drink, allowing you to absorb almost 100% of its content.

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