Raw hide mallet - for hitting punches, etc. Will not deform tools.
The mallets come from the factory with a hard shellac coating. The coating must be removed first. Use a coarse rasp and alcohol to accomplish this. Then you need to soften the surface by pounding on something hard to break up and loosen the rawhide fibers. Find something clean and hard that won't shed particles that will stick to the rawhide (i.e. concrete) - use the edge of a piece of a metal plate instead. It takes time and effort, but so worth it. It won't look pretty, but the gnarlier it looks, the better it works.
42mm By the each.