Features 1、Made of premium diamond material with high hardness, durable in use 2、Strong opening performance, fast drilling speed, smooth drilling without seamless 3、Application: Suitable for drilling marble, concrete, granite, tile, glass, etc 4、Adopting high quality diamond brazing technology, the tooth blade is sharp, the opening hole is smooth without broken edges, and there is no tremor phenomenon 5、Chip removal hole design, conducive to chip removal Specification Features: Made of premium diamond material with high hardness, durable in use Strong opening performance, fast drilling speed, smooth drilling without seamless Application: Suitable for drilling marble, concrete, granite, tile, glass, etc Adopting high quality diamond brazing technology, the tooth blade is sharp, the opening hole is smooth without broken edges, and there is no tremor phenomenon Chip removal hole design, conducive to chip removal Can be installed on the electric drill easily for labor-saving Specification: Material:diamond Weight: 37 g-85 / 1.3-3 oz(approx.) Note: 1. The hole opener is installed on the electric drill. Since this kind of hole opener does not have a center positioning bit, please operate it carefully and pay attention to safety 2.Speed can't be too fast, keep slow speed 3. Keep adding water for cooling. Dry drilling is strictly prohibited, otherwise high temperature friction will affect the use effect Package List