Good quality leather hole punch. Makes holes from 2 - 4.5 mm. The key to keeping these in good working order is to A) - not punch holes in things you shouldn't, like metal, and B) - make sure the punched out circle clears the tube and doesn't interfere with the next punch. Lever on the side locks it closed for transport or storage. Rugged metal construction. Coated handle for better grip.
By the each.