Montane Ultraflask 500ml

The Montane Ultraflask 500ml is a collapsible TPU soft flask designed to shrink as you drink, so it never sits half-empty and sloshing in a running vest pocket or hip belt pouch the way a rigid bottle does. At 37 g, it fits the standard profile for soft flasks aimed at trail running and fastpacking rather than general hiking, where a rigid bottle typically holds up better to rougher handling. The closure pairs a wide screw-top opening with a high-flow silicone bite valve, letting you drink on the move while running or hiking and refill quickly from a stream or container. Montane rates it leak-proof, made from BPA-free material, and dishwasher safe. It has no built-in insulation and isn't rated as filtration-compatible, so it won't double as a filter bottle or handle hot liquids. With no carry loop or carabiner attachment, it's meant to live inside a vest or pack pocket rather than clipped on the outside.