The Tretight dock seal consists of four main parts - the top cushion, the two side cushions and the fitting set. The three cushions are separate units that are made in a chloroprene rubber coated synthetic fabric. The load bearing construction consists of two side brackets, two wall plates and a front plate. This is covered with a corrugated steel roof. The fan is placed under the roof. The retraction of the top cushion is done by a counter weight and the side cushions are pulled aside by elastic cords.