Blue Sea M Battery Single Circuit ONOFF Switch w Locking Key This Blue Sea M Battery Single Circuit ONOFF Switch w Locking Key features a one-piece terminal stud design that never loosens over time. It offers breakout tabs that allow wire access in any direction and has an isolating cover that protects rear contacts. With one-piece stainless flange nuts, this switch ensures safe and secure connections. The tin-plated copper studs allow for maximum conductivity and corrosion resistance. Features