Blue Sea M-Series Mini Single Circuit Switch w Key The Blue Sea Mini Single Circuit Battery Switch switches a single battery to a single load group. This battery switch features a case design that allows surface, front panel, or rear panel mounting. The one-piece terminal stud design never loosens over time studs are tin-plated copper for maximum conductivity and corrosion resistance. The isolating cover with three snap-off side pieces protects rear contacts and allows wire access in any directi