Excerpt: I bought these to work with my Philips DVT5500 Digital Voice Recorder. I use them for emergency situations when I'm away from home or office and am either reduced to using a pay phone, a hotel phone, etc. where I can't use my regular gear to hook up my recorder to the phone system.
Summary: I bought this one and the Olympus TP-8 Telephone Pick-up Microphone Device both from Amazon. I tested them both. They work well. conversations are clearly replayed on my recorder. worth it. I like the Philips better just for the roll-up thingy that makes storage a little more convenient.
Generally speaking, it does what it's supposed to do ...
Dave K., Amazon
5 July 2013
Summary: Generally speaking, it does what it's supposed to do. I would have hoped the gizmo to take up the slack would be a little smoother, and I've had slightly clearer sound from other models but those are minor concerns.