The M252 system weighs 91 lb (41 kg) completely assembled and is composed of the M253 Cannon (35 lb, 16 kg), M177 Mount (27 lb, 12 kg), M3A1 Baseplate (29 lb, 13 kg), and the M64A1 Sight Unit (2.5 lb, 1.1 kg). The mount consists of a base plate and a bipod, which is provided with screw type elevating and traversing mechanisms to elevate/traverse the mortar. The M64A1 sight unit (also used on the M224) is attached to the bipod mount. The M252 is a gravity-fired smoothbore system. Attached to the muzzle of the weapon is the Blast Attenuation Device (BAD), used to reduce the blast effects on the mortar crew. To increase cooling efficiency, the breech end is finned; though first-hand accounts attest that the level of cooling is negligible. The cannon also has a crew-removable breech plug and firing pin.