New Other Hydrogen Flask Standard Mouth Flex Cap Graphite, 21 Ounce Everything else included cushioning system adds energy returning responsiveness Black Charcoal cushioning system adds energy returning responsiveness Anatomical lace system reduces pressure on the foot for added comfort Sock like bootie construction and TPU stability wrap improve fit Mesh tongue and heel insert provide breathable comfort Grippy rubber outsole wraps up and around the midsole to add traction Rear facing Liquids Remain Hot Up To 6 Hours Your Bottle Stays Slip Free Making It Easy To Go Wherever You Do Fits In Most Automobile Cup Holders And Bicycle Bottle Racks