Klean kanteen caf cap 20 wide black the leakproof caf cap 20 wont leak or spill and turns any insulated wide product into an instant to go mug throw it in your bag or stash it on your bike now its even easier to bring your own hot or cold drinks anywhere you go made from bpa free polypropylene pp5 and food grade silicone this cap is safe for use with acidic or hot beverages features low profile cap creates a leak proof to go mug with one twist large silicone valve ensures fl