A PAIR(2) RV Boat Nitro-Prop Gas Strut Spring Shock Lift Rod Piston 15" extended length x 9.5 " compressed length x 50 LB Pressure Extended Length: 15" (center to center of ball socket ends) Compressed Length: 9.5" Force: 50 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two