A smooth-gliding slider covers the mouth opening of the MiiR Press-fit Slide Lid for an extra dose of insulation and splash proof piece of mind. Available in 2 sizes to fit all MiiR Tumblers, all Camp Cups and Lowball & Highball.  Note the Press-fit Slide Lid is not leakproof.* Large size fits 12 oz., 16 oz., 20 oz. and 24oz. classic Tumblers & all Camp Cups. Features: Splash proof Shatter proof Dishwasher top rack safe BPA free Available in 2 sizes to fit all MiiR Tumblers, all Camp Cups and Lowball & Highball Product to Project® Every MiiR product sold helps fund trackable giving projects. Just enter your code.  *Note that changes in elevation and exposure to high temperature environments may create pressure inside your bottle. Safely release it by slightly twisting the Straw Lid open and closed before opening the spout.