Rock-N-Rides kids will rock around the clock with rock-n-rides! Each durable one-piece cast aluminum unit is built to endure active kids – and Mother Nature. Every unit incorporates an exclusive enclosed rubber spring (boot) to prevent pinching and provides a smooth, controlled ride. The plate is 10″ x 10″ and holes are 8 1/4″ center to center. These are all designed for use by one child under adult supervision.