Feature: 1.double row, metal body 2.good balance 3.lifespan 6-8times of press steel 4.soft, mid-hard and hard bond separatly Usages:1. For stones such as granite, marble, natural and artificial stones, etc.2. For fast rough dry or water-cooling grinding, leveling, shaping and polishing stone surface, corners,edges and angles. Other sizes and types as below:- Size(inch)3, 4, 5, 6, 7TypeSingle Row, ...