12V DC 4 pin relay switches are the best solution for full voltage applications, as they allow a low current flow circuit to control a high current flow circuit, like a vehicle’s horn.

A 12V DC 4 pin Relay Single Pole Double Throw (SPDT) switch is a switch that only has a single input and can connect to and switch between the 2 outputs.

This means it has one input terminal and two output terminals. A Single Pole Double Throw switch can serve a variety of functions in a circuit

General Purpose Relays are electromechanical switches, usually operated by a magnetic coil.  They can control currents ranging from 40A.

The SPDT Relay is a high quality Single Pole Double Throw Relay(SPDT). The Relay consists of a coil, 1 common terminal, 1 normally closed terminal, and one normally open terminal.

When the coil of the relay is at rest (not energized), the common terminal and the normally closed terminal have continuity. When the coil energizes, the common terminal and the normally open terminal have continuity.