MIL-T-9720 Truck, Lift, Aerial Stores, 3000 Pounds Capacity Mj-1A And Mj-1BThis specification covers two types of self-motivated, power hydraulic lift trucks. Type I - Powered by a 4 cylinder gasoline engine, MJ-1A Type 2 - Powered by a 2 cylinder diesel engine, MJ-1B.