Our Premium Double Row Style Grinding Cup Wheel is double laser welded and contains 40%-44% diamond concentration. We use a 30-40 grit, grade 10 GE diamond that will hold up to the most abrasive concrete you'll ever come across. Used with your grinder, you will fly through concrete like a hot knife though butter! Available in 2 arbor styles 7/8 with 5/8" bushing or 5/8 - 11 Threaded