This Plantronics CA40 DECT Adapter System, comes with battery pack and a cordless TriStar noise cancelling headset. 

The CA40 is listed on the Poly website as a "...long-range DECT™ cordless headset system, combining excellent sound quality and easy installation".

The equipment is in a good used condition but has not been fully tested since I stopped using it a few years ago, hence listed as For parts or not working.