Phone plug to 2.5mm jack adaptor - does it exist?

I recently got an over-the-ear headset similar to this one. I got it for free from a friend, so I’m not complaining… except that that it ends in a 2.5mm plug. My telephone doesn’t have a jack for a 2.5mm plug. It only has a regular, US RJ-11 plug.

I tried Googling around, and I stopped by the local Radioshack, and I can’t find any adaptors that would allow me to use this headset with my phone. Does such an adaptor exist?

Any help would be appreciated.

I think that 2.5 mm headsets are generally intended to work with cell phones or portable cordless phone outputs. Even if a size adapter was available it would probably not work properly with a wired phone’s audio IO.

I believe you may be able to find headset adapters for desktop phones. It isn’t just a simple electrical connection.

You can buy an adapter that plugs into the module jack of a telephone and allows you to use a regular computer headset/microphone.

Usual purpose of this is to be able to switch btw Computer Speech Recognition and talking on phone via same headset.

The painful part is that you need to use the switch hook to answer or call out, so you end up keeping the handset in the cradle but disconnected…

I had an Andrea unit to do this for a while, but new electronics in office made for lots of feeback and I gave up on it.

My 2 line desk phone has a headset jack anyway, so I can use a cheap Plantronics Headset via the built in jack, and use the “headset” button to pick up calls or dial out.