The GRP webs have a standard thickness of 3, 4 or 6 mm but the height can be chosen freely. The manufacturing process for these “hybrid profiles” is very flexible and allows to produce small batches with 500 kg only. For bigger projects there is the possibility to customize the GRP profiles by pultruding undercuts or dovetails in to the web to accommodate special fittings like gaskets or seals. The profiles can be produced with rounded corners or sharp corners (external radii below 1 mm) by using cold drawn or laser cut flanges. The maximum bar length is of 8.000 mm and the sizes start at 30×30 mm and go up to 200×200 mm. These products are mainly used to manufacture thermally insulated window and door sections, frames for climatic chambers, electric rails or stiffening sections for plastic window frames.