4 Inch 4" Stroke Linear Actuator 12 Volt 12V 225 Pounds lbs Maximum Lift Maximum current draw = 4.6 Amps Maximum Dynamic Load = 225 lbs (900N) Maximum Static Load = 600 lbs Retracted length: 8.13&#034;(205mm) Extended length: 12.13&#034;(305mm) Diameter of Mounting hole: 0.256&#034;(6.5mm) Diameter of Shaft: 0.79&#034;(20mm) Linear actuators are actuators which create motion in a straight line. Unlike a motor, which creates circular motion, a linear actuator can be used with any application that requires moving something in a straight line. Demotor Linear Actuators are a powerful and reliable linear actuator for small to medium loads.