Brownell Trailer Mounted Boat Lift 7,500 lb Capacity. Mounts securely to your trailer frame. It is designed to safely lift a boat (up to 7,500 pounds) enough to clean or paint the bottom while it rests on the trailer. Designed to fit trailer frames with beams that measure 2"-3" wide and 4.5"-5.75" high. Will not fit on other size trailer beams.