CA12CD-S/CA12CD both discontinued
Plantronics discontinued the CA12CD unit quite awhile ago. The CA12CD-S is NOT the same thing and the remotes cannot pair to each other’s bases.
SO, if your Customer is having trouble pairing a push-to-talk remote to a base, check to make sure they match. You can find model numbers on the bottom of the base.
Another dead give-away is the buttons on the base. The base for the CA12CD (the older, discontinued model) are black. The buttons on the CA12CD-S are dark grey. Otherwise they look really similar! So help your Customer out and make sure they’re set up for success!