Surge arrestors protect against lightning, utility switching, isolation arching, electrical motor cycling, or any other sudden change in electrical power flow on incoming AC power lines.

Indoor surge arrestors are mounted within panels, distribution boards or mini-substations where equipment needs to be protected against incoming surges and transients. The 1,2 meter tail provides the connection onto the supply, whilst the bottom of the surge arrestor is mounted onto the earth point. The bottom centre hole is a 10mm thread, which is bolted onto the earth point, and is available from 3kv-33kv.