A PAIR(2) Tanning Bed Gas Spring Strut Rod Shock Lift Prop Arm Tube 20.5" extended length x 13.7 " compressed length x 152 LB Pressure Extended Length: 20.5" (center to center of ball socket ends) Compressed Length: 13.7" Force: 152 pounds of pressure (Per Prop) End Fitting: 10mm Ball Socket and 10mm Ball Socket Set of Two