Two 1" diameter stainless wrap around rails. Durable HDPE platform is pre-drilled for easy assembly. Mounts at 10 degree angle on transom. Ladder steps telescope down easily. Ladder slides up and under platform for stowage. Flat poly treads for extra comfort. 18" W x 15.5" D X .75" Thick. Height above platform: 12.5". L deployed: 22.75", L Stowed: 17". Overall height: 5", W: 13.5".