A cone shape at the base section with a cylinder section on the top half made of brass and is screwed onto the rear section of and Arial Bomb. There are 2 leavers either side of the cylinder section which open out after the bomb has been dropped from a plane ,this helps slow the bombs decent and with a brass propeller at the very top of the devise helps to activate the firing pin and arming the bombThere are a number of Japaness markings on the cone section with some numbersww2 japaness bomb arming mechanisum