Used for fastening to a bolt when mechanically joining materials together and preventing loosening from vibration or back off. The hexagonal shape provides increased leverage for use with a wrench during installation and disassembly. Constructed from carbon steel, surface is zinc-plated for good rust resistance. Specification:Material: Carbon SteelSurface Treatment: Zinc PlatedThreaded: G3/4"Hex Width: 32mm / 1.26"Height: 5.5mm / 0.22" Package Content:2 x Pipe Fitting Hex Locknuts