Thanks to a clever adaptation and using the already proven 20 mm threshold, our house and patio doors, double and central seal systems TROCAL 76 and central seal systems TROCAL 88, become barrier-free threshold solutions. In the case of belt profiles, the internal overlaps of the belt are shortened and equipped with a special closing strip. Connection brackets coated with EVALON and connection plates made of stainless steel, specially designed for the system, allow professional connection of sealing membranes and professional installation of gutters. The threshold is at ground level on the outside, there is a step of 10 mm on the inside.