Thomson D12-20B5-04, Electrak 10 Actuator, 12 Vdc, 1000 lbf Capacity, 20:1 Gear Reduction, Ball screw, 4 in Stroke, 0.45 in/s Travel rate Robust, strong and reliable Stainless steel extension tube Highly efficient ball screw drive system Overload clutch for mid and end of stroke protection Motor with thermal switch