This concealed joist hanger is a high - quality, versatile building component crafted from Q235B steel with a 2 mm (0.08 - in.) thickness, featuring a black powder - coated surface that offers excellent waterproof and rust - proof properties. With a size of 2 in. X 4 in., it is specifically designed to fit 2 in.x 4 in. wood hangers and allows for installation around existing structures without compromising structural integrity. Its practical design simplifies the installation of joists and wooden beams, enabling quick setup of visually appealing, professional - looking beams that effectively conceal the installation. The package includes 12 joist hangers, along with 24 self - tapping screws, 120 wood screws, and a drill bit. This multi - purpose hanger is suitable for both indoor and outdoor use, facilitating the installation of beams and handrails indoors, as well as being ideal for outdoor structures like backyard cabins, gardens, swings, and playgrounds.