1、Spillproof: The replacement lid has a sealable thrust slider, which no longer worries about the overflow of water or drinks. There is also a check valve hole at the top of the slider to help prevent from splashing. 2、Silicone Gasket: The edge of the flat bottomed cup lid is lined with a black silicone gasket, which can help firmly cover the cup and effectively prevent splashes and major spills when the cup is turned over. 3、PP and AS: Made of safe and reliable PP and AS materials, the 30oz tumblers lid is corrosion and heat resistant, odorless and can be used for a long time. 4、Easy to Open and Close: Switch sliding cover design, easy to use. The hole on the top of the cup can be used directly or with a straw. The sliding cover design prevents you from touching your nose while drinking water. 5、30oz Tumblers Lids: The lid cover can replace 30 ounces insulated car cups. Applicable to various scenarios, going out, self driving traveling, or daily use at home.