For system design. The rockers are plugged onto the 2-way button module. To be completed with: Basic button module, 2-way system design MEG5120-60.. Comfort button module, 2-way system design MEG5121-60.. Wiser button module, 2-way system design MEG5123-60.. Extension Plus, 2-way system design MEG5129-60.. Material: Brilliant thermoplastic. Color: lotus white.