A PAIR(2) RV Boat Nitro-Prop Gas Strut Spring Shock Lift Rod Piston 28" extended length x 16.5 " compressed length x 90 LB Pressure Extended Length: 28" (center to center of ball socket ends) Compressed Length: 16.5" Force: 90 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two