A Pair of Gas Prop Lift Springs Rod Struts Heavy Duty Tool Box Lid Top RV 13" extended length x 8.1 " compressed length x 30 LB Pressure Extended Length: 13" (center to center of ball socket ends) Compressed Length: 8.1" Force: 30 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two