The technical detail: > By pressing a button on the remote, you set off a spring-loaded hammer that strikes a solid aluminum rod in the device, which then ring

The technical detail: > By pressing a button on the remote, you set off a spring-loaded hammer that strikes a solid aluminum rod in the device, which then rings out at an ultrasonic frequency. Each button has a different length rod, thus a different high-frequency tone, which triggers a circuit connected to a microphone in the television to finish the command.