The Flow is a 350 ml stainless steel tumbler that uses quality foam insulation to preserve the contents’ temperature. Drinking is easy via a leak-proof, push button system that only requires one hand to operate. The button is rubberized for slip-proof grip which also matches the characteristic overall smooth feel. With its integrated silicone strap, the Flow is also easy to carry or fasten to bags or other gear. The Flow tumbler is one of a trio of matching drinkware items which also includes a drinking bottle and a isolating flask.