A mechanically concealed attachment system option for rainscreen cladding applications that utilizes KEIL undercut anchor technology. A wide variety of facade cladding products can be attached mechanically and can be concealed using undercut anchors. The backs of the cladding elements are provided with cleats with special bolts that are inserted into the undercut hole and fixed by tightening the screws. Each cladding element must be fastened with at least four individual anchors.