These diamond grinding pads are triangular type. The function part is the electroplated diamond dots which used for grinding granite, marble, concrete, and other types of stones. 3-inch velcro backed pad can be used dry or wet on oscillating tools like Fein, Dremel, Bosch, Dewalt, etc. It's easy of these stone grinding pads to reach corners and edges of the floor. Sunny Superhard Tools provides you high-quality of concrete grinding pads in various diamond grits. Electroplated grinding pad in various diamond grits for grinding concrete, granite, marble and other stones. Triangular type with a velcro back designed to be used on oscillating tools. Easy to reach corners & edges of the floor.