Made of smoothly finished hardwood, this block includes six hammer punches with corresponding head diameters to work with the six u-channels in the block. Widths of U-channels and hammer punches measure: 25, 22, 18, 16, 13.5, and 11 mm. On the reverse side is a 90 V-groove which is perfect for forming angles; the width of the V-groove is 10 mm.