Specifications:Using high quality diamond material, it is very durable, wear-resistant and easy to use.This product can make fast and smooth drilling, which is long-lasting, chip-resistant and shatter-resistant.It is suitable for opening holes in stone, ceramics, vitrified tiles, glass, etc.Item Name: Hole OpenerMaterial: DiamondQuantity: 3Pcs/SetProduct Models: 38mm, 40mm, 45mmFeatures: Durable, Long-Lasting, Shatter-ResistantSize: 38mm/1.49", 40mm/1.57", 45mm/1.8" (Approx.)Notes:First, it is positioned at a 45 inch bevel, and drills vertically, the speed should not be too fast, then the speed should be slowly operated at about 800-1000 rpm, and water must be added to cool the operation.Due to the light and screen setting difference, the item& 39;s color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x 38mm Hole Opener1 x 40mm Hole Opener1 x 45mm Hole Opener