Avaya Brand Partner Telephone Headset Base Adapter. The Avaya Partner Base Adapter allows for One-Touch operation of your headset when used in conjunction with a Partner telephone set. With this base and a Partner telephone to take a call you simply touch one button on the base unit. To hang up you simply touch the same button on the base unit. The Partner Base Adapter does not include an Avaya Headset top. The Avaya Base Adapter is shipped complete only the headset top is required.