A PAIR(2) Gas Strut LEER truck topper rear door lift 18.7" extended length x 10.82 " compressed length x 40 LB Pressure Extended Length: 18.7" (center to center of ball socket ends) Compressed Length: 10.82" Force: 40 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two