DELTA fläche IP44 AP button 1S with window and window set (light/bell/door opener) Our surface-mounted DELTAfläche IP44 range offers you an attractive design, increased safety and easy operation. The surface-mounted DELTAfläche 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 risk of contact. DELTA switches and sockets - design and quality in perfection from Siemens.