Heavy Duty & Anti-rust: Our bar stool swivel plate are made of black power-coated steel, sturdy and durable,rust and corrosion resistant, no easy to break 360 Free Rotation: This flat swivel plate is full of ball bearings and no need a plastic race to keep the ball bearings separated apart from each other. This also means better at distributing weight and a longer lasting smoother running swivel Easy Installation: Even if you are not good at DIY, it is easy to install. Hole pattern fits most boat seats & bar stools Wide Application: These 8" bar stool swivel are perfect for replacement use on many stools, such as chair dining, table, TV, sofa etc Package Included: Each package included 2 PCS chair swivel plate (Mounting hardware are not included