These copper Base diamond plated laps are manufactured exclusively for American's Glassworks. We use a copper laminated fiber-board substrate (similar to computer circuit board material), with 100% natural DeBeers diamonds electroplated onto the surface with nickel. This creates a highly durable, rust free disk for all your grinding needs. The back of the disk has a rubberized magnet applied to it which allows for easy application to the metal wheel head of your grinder. This magnetic system makes changing from one grit to the next extremely easy. If you don't currently have a diamond grinder, please consult our diamond plated laps.