Critter Cover will keep your tumblers clean of dirt, hair, lint, and bugs. Fits most 20oz. and 32oz. tumblers. Also fits imagination3d 6 pen adapter. ****Not responsible for wrong size orders**** If you need help measuring I can be reached at Imagination Glitter co. on Facebook. Last pic is how you measure. If the says about 3/4 of an inch from side to side of pvc then you need the 1/2 inch kit. If it measures a little over an inch from side to side then you need the 3/4 inch kit. Plastic tubing thickness is 4.75 mil