Telephone Adaptor for use with a Grandstream HT801 ATA and
Grandstream HT801 or HT802 ATA. on the HT801 / HT802. Grandstream HT801 / HT802. ( I have modified this for use with the Grandstream HT801/2 ). do not always work with Grandstream. RJ11 Plug to BT Socket Adaptor.