DMT Wallet Diamond Sharpener 2 x 3 1/4 x .05 inch Coarse. Take your sharpening anywhere with the ready-to-go Dia-Sharp(R) credit card sized diamond sharpener. Fits easily in pocket or wallet. Comes in convenient vinyl color-coded (Blue) carry case. Coarse diamond (45 micron / 325 mesh) to quickly restore a neglected edge.