The NFA U2 mains field switch monitors the circuit and switches off the mains voltage as soon as the last consumer is switched off. This also switches off the electrical fields. The monitoring voltage is only 2.5V DC. The use of such devices is particularly recommended for bedroom circuits (quiet zones). With the very compact NFA U2, installation in a junction box allows a circuit to be divided into a monitored and a permanently supplied part, which makes installation much easier, especially in older systems., TVE/TVA - 0.1/10s, monitoring voltage 2.5V DC, operating voltage 230V AC, 1 NO contact 10A, dimensions: 18x55mm