Accessories For Your FM System or Personal Amplifier
Manufacturers always suggest that you use only their listening accessories. Their technical specifications are based on using their own components and if you change listening options, it may affect the output specifications that you can expect from a system.
Most systems have a 3.5mm mono jack (one ring on the pin) but there are a few with a 2.5mm stereo jack (2 rings on the pin) for their listening options.
Microphone Combiner Box A combiner box that allows you to plug up to 4 microphones or neckloops to share input or output of a personal listening system.