A deadly close-quarters weapon, now made much less deadly but even more close-quarters. Nice decorative piece, or can be worn as a pendant / keychain with slim cord looped around. Based off of the model in Halo: Combat Evolved.
Supply your own cord, or grab one from Shapeways directly:
https://www.shapeways.com/product/2MTNFZEWS/chains?optionId=63684271