Includes: 2 Gas Prop Lift Support Rods. Extended length: 20"; Compressed length 11.41"; Rod Diameter 8 mm; Force: 150 lbs; Fits standard 10 mm ball studs. Length measurements are center of socket to center of socket. Designed to meet or exceed OE specifications, for many applications (hood, hatch, RV, camper, toolboxes, etc.). Note: Replacing gas props or lift supports in pairs is always a good idea in order to keep the load balanced, maintain even resistance and avoid uneven wear.