I used to use one on my second receiver, an RCA model I believe. It worked OK but I replaced it with a hard-line so I could see the caller id information. At the time RCA made 2 models, mine was the cheaper of the 2.
alot of rca models stated on the package "compatible with caller id",but when you bring it home and read the book....it has a "notice" included in the package saying "this model does not support caller id".......kinda misleading....advertising.so stay away from rca models.
I had the first version out and it was terrible. The second one, which has been out for several years, has been fine. It has been replaced by newer ones since then, and those appear to be as fine as advertised.