Features:
Fits for most 20 and 30 ounces tumblers.
Help prevent spill while turning over the tumbler and keep your drink insulated.
Made from AS crystal clear plastic, odorless and non-toxic.
Strong leakproof function for liuqids, closure with straw friendly opening..
Come with a black silicone o-ring around the base, which helps cover the cup tightly.
An air hole on top of slider according airflow ergonomics which helps reducing splashing.