The Plantronics Headset Adapter Cable is designed for use with Plantronics CS500, Savi 700, and Savi 8200 series headsets. This black cable connects the headset to a device with a headset jack, allowing for seamless communication. With a model number of CS540, this adapter cable ensures compatibility and easy integration with your existing Plantronics headset setup. It is a reliable accessory for enhancing the functionality of your headset system.