VEC VEC TRX-20 3.5MM Direct Connect Telephone Record Device (Adapter ONLY)

Will this work with a cordless telephone and a headset attached to the telephone?

will this work with a nortel phone? it says "please check if your phone system is compatible-with this adapter" but it doesn't list compatible systems

I have a Olympus VN-702PC Voice Recorder and a land line phone. Is this the only other piece of equipment I will need to record calls?

Does not record