SPDT On-On-Off

Off-On (B, R & A) - On (B, R & H).

Brass housing
Four brass screw terminals.
Chrome-plated brass knob, 10-32 thread.
Brass mounting stem 3/8"-32 thread, 1 1/4" long (31.8mm) fits panels up to 1" thick (25.4mm).
With brass facenut, washer and hexnut.
10A at 12V, 6-36V DC.

Offsite info on Marine Navigation Light wiring.