A PAIR(2) RV Boat Nitro-Prop Gas Strut Spring Shock Lift Rod Piston 20" extended length x 12 " compressed length x 60 LB Pressure Extended Length: 20" (center to center of ball socket ends) Compressed Length: 12" Force: 60 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two