Shielded aluminum alloy,protect network signal, fit video & data protector device. For control signals,computer network signals, hubs, network cards, network switches, Modem, fax, data communication. Mulit-level protection, flow capacity, low clampling voltage, fast response time, low insertion loss, transmission rate advantages. Special maintenance is not needed for the protection device; please replace immediately in case of damage by high voltage or . Protectors have input (IN), output(OUT) mark, output terminal and protected, donnot connect the device to connect. Otherwise it will cause the protector the damage.