The styropor wedge with dimensions of approx. 100 x 13.5 x 5 cm (L x W x H) is specially designed for laying a fillet at the transition between the steel shell or bottom rail and the bottom insulation in the steel wall pool. This fillet prevents kinks and creases and is an essential step for reliable protection of the pool liner. The Styropor wedges are attached directly to the inside of the steel wall using a suitable special adhesive. During installation, make sure that the pool liner is laid without creases to ensure maximum durability.