DELTA replacement window for light signal 2x clear, 2x red, 2x white Our surface-mounted DELTA surface IP44 range offers you an attractive design, increased safety and easy operation. The surface-mounted DELTA surface IP44 range impresses with its break- and impact-resistant thermoplastic housing. All switch and socket inserts have screwless terminals for wiring. With the insulated release levers you can release the conductors without tools and without touching them. DELTA switches and sockets - design and quality in perfection from Siemens.