Made of smoothly finished hardwood, this U-Channel Hardwood 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. Width of the v-groove measures 10 mm. Weight: 12 oz.