The Frontier Series II RED Line Filter keeps you safe from waterborne illness in any circumstance. Use this filter with a Frontier Flow bottle to easily refill from any water source and carry up to 22 oz.
With the BeFree™ 0.6L Filter, you no longer have to worry about where your next drink will come from. Just fill up the flask and let the EZ-Clean Membrane™ do the work. Gently squeeze the flask for instant refreshment.