HDPE washer clips onto the bracket and separates it from the buildings structure preventing from corrosion. It has very low thermal conductivity and minimizes so called “thermal bridges phenomenon”. Washers come in three sizes: 60, 120 (made of two 60 mm pieces) and 150 (made of 60 and 90 mm pieces) which cover full range of BSP brackets. They are 5 mm thick and come with pre-drilled anchor slot.