Used as an alternative to concreting and as an extra safeguard for polytunnel construction and durability. Essential on polytunnels fitted with Base/Side Rails. A square plate slots over the foundation tube and is fixed at the base of the tube through the use of clamps. Once in position, the plate will prevent lifting and sinking of the framework. The foundation tube shown is not included in the price. Three sizes available 25.4mm, 35.0mm and 50.8mm.