The design of the plate stands out for its curved-convex profile. An included cellular rubber sealing gasket ensures a perfect fit of the plate to the wall, to avoid water leaks. It is possible to combine two or more plates, provided they are from the same series. To fit them perfectly, a set of spacers should be used every two plates that are installed between their embedding boxes. Aluminum color. Call buttons: metallic and rounded in line with the curved profile of the plate. The pressing of the call button is confirmed by an acoustic warning light emitted by the amplifier. Wiring: 4 common wires + N (1 call wire per home). 12 VAC supply. IPK-437.