A switch that connects and disconnects a load resistance to a video input, used to terminate the line. In order for a video signal to be correctly transmitted without loss, proper end of line impedance is essential. Amplitude errors and reflections will otherwise result. A 50- or 75-ohm resistor is usually employed to accomplish this. When the termination switch is off, the unterminated video signal is looped to the next device where the signal can be transmitted in parallel. The final device in the chain must be terminated using the termination switch.