SpecificationThis lid fits mugs with a 3.15-3.2 inch inside diameter at the mouth. The insulated mug lid is made of thick sturdy plastic.The plastic lid is transparentallowing you to easily see the water in the cup and the water level.You can easily open and close the sliding tabs by using the sliding blade on the top of the nonpareil.The rubber seal on the bottom of the lid fits snugly into the Yeti tumbler. Based on airflow ergonomicsthe top of the 30 oz.Non Tumblers sliding lid is designed with an air hole to help minimize water splashing.If your original lid is broken or missingyou can replace it.A tumbler with this lid also keeps drinks cooler and longer. It is easy to clean and dishwasher safebut avoid using it in the microwave.The air hole design maintains the same air pressure inside and outside of the nonpareil making it easy for you to drink. This lid prevents accidental tilting and spills.When filling hot drinks it is best to open the straw hole to prevent the lips from popping up due to high pressure.Package Includes2 x Spill and splash resistant tumbler lids