This 20 inch 180 lb gas spring shocks are widely used on heavy lids such as heavy duty bench box lid, boat hatch or floor hatch cover, truck Camper RV bed, Murphy Bed,AD board, or home-build window, etc. Product Description: Force: 180 Lbs Per Strut Extended Length (Center-to-Center): 19.7(500mm), Compressed Length (Center-to-Center): 11.8(300mm), Package: 2 Pcs 800N/180lb 20 inches Gas Strut and Screws This comes in a pack of two, not one! The shocks arrived in extended, couldn't be compressed by hands before installing! Message us if you need help with installing or the product itself!