The Plantronics M22 amplifier base is a durable and very reliable headset amplifier base designed for use with Plantronics H series headset tops. Not all phones have a headset port so the M22 allows use of a wired headset for those models that don't have this port. The short coil connector cord plugs into the handset port of the phone and the headset top into the longer coil cord with quick disconnect.
Having the quick disconnect feature allows you to simply plug in to use the headset and if you need to step away while on a call, simply unplug. Your call isn't dropped and when you reconnect, you're back on the call. The M22 has several helpful adjustments.
You can adjust the hearing volume as well as the volume of your voice to your callers. You can mute the microphone when needed but when doing so, you can still hear the caller. There are several compatibility adjustments which allows the M22 to work with 98 percent of all office desk phones. The M22 is powered by two double A batteries which are included and last a long time before needing replacement.