Carpeted bunk boards provide proper center loading even in wind or side current conditions. Marine Grade 2" x 4" x 5’ Boards tilt and are covered with height grade marine carpet. Distance between galvanized upright posts can be adjusted to fit trailer. height of 21" with adjustment out to 13" each side. Can be mounted on top of frame for extra height. Complete kit to fit frames up to 3" Width x 4 1/4’ Height. Display packaged for easy merchandising.