Function is good, except for the annoying whistling

As already described in the other reviews: great feature and it works together with 4 or more buttons with glow lamp, where many other relays can not cope with it (because of the high Glimmlampenstroms).

But: In the state of the relay is an annoying whistling sound of itself, therefore 2 star deduction. It is also not the bulbs used, even in normal light bulbs whimpers the relay. Even if the cabinet is closed, you can hear it clearly. Who does not bother, because the cabinet is like in a basement and out of earshot, can access safely. Glow lamps Otherwise rather resort to an electromechanical relay, provided are not an issue.