Coming Soon: Select GSI Outdoors Products!
Your favorite beverage can now go anywhere in the Boulder Flask. Includes graduations for measuring and can take any fall with the sleek bumper flask.
Thermoplastic resin body
Tough and shatter-resistant, the Boulder Flask can stand up to nearly any outdoor adventure; Thermoplastic resin body keeps your drink of choice intact
Wide mouth opening
Wide mouth opening makes for easy filling, pouring and drinking; Molded graduation marks help you quickly measure or see what’s left while you’re on the trail.
See-through design
See-through design for a fun and novel drinking experience; Hinged top with grippy silicone bumper makes for easier opening, helps prevent leaks and ensures you won’t lose the cap.
Lightweight
Weighing only 4 ounces empty, the Boulder Flask won’t weigh you down even after you fill it.
BPA-free
This BPA-free flask is durable, safe to drink from, and doesn’t have any foul or “off” aftertaste.