Elite Turacio Thermal Bicycle Water Bottle - 500 ml 100% Natural cork insulation is light, flexible and fully biodegradable The advanced membrane valve and sealable bottle top make this bottle absolutely leak-proof, perfect for taking in your car or down to the gym Membrane valve uses taste-free medical-grade silicon and delivers 47 ml per second with minimum effort The cap fully disassembles for easy cleaning and all parts are dishwasher safe 100% BPA Free