A fixed fastener is suitable for installing roof substructures on roofs covered with trapezoidal sheet metal such as Trimo, Armat and similar. Fastener is appropriate for mounting in the transversal direction. Fastener is screwed onto the trapezoid wave with four screws (see product PP SOL-N16 P). The seal ensures water-tightness at the point of fastening. The module clamp is attached directly to the fastener!