The electronically controlled impulse switches ISS and ISS U1 can be used without any issues in environments where conventional electromechanical impulse relays are perceived as disturbingly loud, thanks to their very quiet switching behavior. The flush-mounted version ISS U1 230V AC is also suitable for easily retrofitting existing systems or for renovating older buildings, and due to its compact dimensions, it can be installed in switch or junction boxes. Relay contacts normally open, potential-free, 10A 250V AC, dimensions: 43x43x18.5mm ISS U1.