stitching chisel; pricking iron; multi-prong punch for leather-craft
A leather-craft tool with multiple diamond-shaped prongs used to mark or punch stitching holes evenly.
I use a stitching chisel to punch sewing holes in leather.
This pricking iron has four prongs and can make evenly spaced holes.
Compound of 菱 (ひし, 'diamond shape') + 目打ち (めうち, 'punch' or 'awl'), referring to the diamond-shaped prongs of the tool.