A PAIR(2) RV Boat Nitro-Prop Gas Strut Spring Shock Lift Rod Piston 18" extended length x 10.75 " compressed length x 45 LB Pressure Extended Length: 18" (center to center of ball socket ends) Compressed Length: 10.75" Force: 45 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two