The Beast 20 oz. and 30 oz. Tumblers have a lifetime warranty and a 100% satisfaction guarantee. If you don't love the way our double-wall vacuum insulation keeps your hot drinks hot and cold drinks cold; we'll refund your money. Our stainless steel cups are made of 18/8 food grade stainless steel.
" I love my 30 oz. Tumblers! I use it mainly for water. The water stays cold all day and if I put ice in it, the ice is still there the following day. "