Made up of 304 grade Stainless Steel, Suitable for both indoor and outdoor use, and ideal for harsh environments such as yachts and boats. It’s very durable, corrosion resistant and long lasting, to open position the spring coil becomes rigid support. To close, apply side pressure to the middle of the spring coil and the support will collapse to a closed position. Ideal for the lighter door, lighter cabinet doors, window, lighter hatches, table leaves, icebox lids, bait well, fore hatch, and a wide variety of uses. Not recommended for applications where the hatch will scoop wind while the boat is underway and over-extend spring. Dimensions: Spring Outer Diameter: 7/16 inches (11.0 mm), Length: 8-1/4 inches (210.0 mm). Package Includes: 1 pcs of Marine City Stainless Steel Polished Finish Hatch Spring Adjuster with U-Bolt and L-Shape Plate.