Size: Total length 100mm Pitch: 4mm Quantity: Set of 4 (1, 2, 4, and 6 prongs) This is a 4mm pitch, set of 4 diamond chisels for leather hole punching, a leathercraft tool. The 1-prong and 2-prong chisels are suitable for punching holes in curved sections, while the 4-prong and 6-prong chisels are suitable for punching holes in straight sections. Place the diamond chisel vertically on the leather and strike it from above with a hammer or similar tool. To prevent rust, oil has been applied in advance, so please wipe it off before use. Due to the nature of the tools, there may be small scratches or stains. We appreciate your understanding before purchasing.