The Buckleguy Strap Cutter. Comes with two blades.
This strap and strip cutter hand tool has been the standard for crafters and small manufacturers for decades.
Cuts up to 20oz leather, as well as very soft leathers with ease. It can also cut several other materials including rubber, cardboard, balsa, cork, paper, polyethylene plastic, cane (bamboo), linoleum, vinyl tile (trimming).