MAXIMUM PROTECTION - This durable bottom boot helps protect against dents, dings and damage. Allows your water bottle go the extra mile and extending it's life. TOP QUALITY YOU CAN TRUST - This bottom boot is made of high quality BPA-FREE silicone, Safe for all ages. DIAMOND TEXTURE DESIGN - Diamond shaped texture, 3D surface for added friction and bringing in for a nice feel and better gripping experience. VENT HOLE - Vent hole on bottom allows air to be removed when sliding on, making the silicone boot fit closely to the cup allowing for a more convenient use. FITS PERFECTLY - Compatible with 30 and 40 oz Stanley Flowstate Tumblers, 20 oz Stanley Slim Bottle, 20 and 30 oz Stanley Flip Straw Tumbler and across a wide range of other tumbler brands and sizes. This is a silicone diamond texture bottom protector boots for Stanley 30 & 40oz Flowstate Tumblers. The diamond textures brings a nice feel and better overall gripping experience while projecting an elegant and sophisticated look.