A double-pole double-throw electrical switch actuated by a remotely controllable twin-coil momentary power electromagnet. It can do all sorts of useful jobs on your layout some of which are -Power the frogs on Mark 2 Turnouts to eliminate the short "dead- spot" and prevent stalling of short-wheel-based locos. -Power trackside signal lamps to show switch point settings. -Feed control panel lamps to show points setting of remotely located turnouts. -Selective power control for dead-end sidings with all Atlas turnouts Mark 2 Custom-Line or Snap-Switches. Control X-sections automatically. It can be installed wherever convenient. Four rail joiners are provided. Detailed instructions with schematic display of snap-relay.