This Chug Cap is specially design for Yeti Rambler Bottle ,fits all YETI Rambler Bottle models(18 oz, 26 oz, 36 oz,46oz,64 oz).(Not fit Hydro flask） A bottle is only as good as its cap, the Chug Cap made of BPA-free transparent ABS.Whether with cold or hot drinks, this cap can keep the temperature longer. With a quick half-twist to open the cap and then you're good to go, making it easy to steal a sip without slowing down. Extra-wide opening for easy filling, drinking,cleaning and dishwasher safe. 100% Leak-proof, carry it with confidence.