Part of our ultra-light series, the 500ml is so light you might forget you have it with you. Weighing just over an ounce, it's the optimal hydration no matter what type of runner you are. The pliable material adjusts to fit most pockets, it shrinks as you drink to minimise water movement, and it can be used with or without a tube. The new SpeedFill™ cap makes refilling at aid stations a breeze. Ultralight, extremely useful.

• CONVENIENT FIT The soft material fits most hydration waistcoats, belts or backpack pockets
• COMPACT The flexible design shrinks when drinking and reduces water movement
• ADAPTABLE HYDRATION Choose between a bite valve and a drinking tube closure
• SPEEDFILL CAP With a flip-top cap for quick refilling at aid stations
• A great addition or replacement for your running waistcoat, backpack or fanny pack.
• The fit of the waistcoat provides springy stability and a flexible shoulder section that prevents chafing so you can focus on FKTs and PRs.
• The high-flow bite valve closes automatically after each sip, preventing annoying drips.
• Thanks to the large standard opening of 42 mm, you can easily fill the UltraFlask with ice and drink mixes
• Customise your cap with two options to fit your barrel or waistcoat: Mount your bite valve directly or use the straw cap (4 inch / 100 mm)
• Made from ultra-durable, abrasion resistant TPU & RF welded seams for superior durability and elasticity
• 100% BPA and PVC free, wide working temperature range (freezable - max. 60° C / 140° F)

Capacity: 500 ml
Weight: 41 g
Dimensions: 186 x 58 mm