The Shelly Wall Switch WS1 in black is designed as a replacement for conventional light switches. The 1-button switch is supplied with extendable relay holders. Thanks to its compact dimensions and simple wiring, the Shelly Wall Switch for Smart Relay can be installed in any existing flush-mounted box or even in the smallest of rooms. Relay holder 1 - Shelly 1 / Shelly 1PM. Relay holder 2 - Shelly Plus 1 / Shelly Plus 1PM. Relay holder 3 - Shelly 1L / Shelly Dimmer. Due to the extremely compact design, installation can be realised even where space is limited, which is particularly advantageous in old flats and houses. Scope of delivery: 1 x Shelly Switch WS1 black. 3 x relay holder. The Wall Switch frame WF1 is not included in the scope of delivery and can be purchased as an option.