Heavy-duty cast-zinc construction with satin nickel finish. High-quality torsion-specific system. Allows any size lid to open smoothly, hold its position and easily close. Unique torsion mechanism holds lid in any position without using lid support. Suitable for overlay and flush-fitting lids. Hinges can be interchanged and combined to create exact resistance for the size of the lid. Includes screws. Fits 19mm (3/4") thick stock.