Barrack buster is the colloquial name given to several improvised mortars, developed in the 1990s by the engineering unit of the Provisional Irish Republican Army (IRA). The improvised mortar properly called "barrack buster" - known to the British security forces as the Mark 15 mortar - fired a 1 metre (3 ft 3 in) long metal propane cylinder with a diameter of 36 centimetres (14 in), which contained around 75 kg (165 lb) of home-made explosives and had a range of 75 to 275 metres (246 to 902 ft). The cylinder is an adaptation of a commercial gas cylinder produced by the Cobh company Kosangas for heating and cooking, and used in rural areas across Ireland.