National Geographic Magazine, March 1990 (Vol. 177, No 3)

RJ9 4P4C to 3.5mm Audio Adapter for Cisco IP Telephones - Headset Converter Compatible with 9961, 7940, 7941, 7942, 8841, 8845, 9941 | Model PH35-RJ9 (Audio Combo Jack)

Earsinger RJ9 Male to 3.5mm Female Plug Headset Jack Phone Adapter Cable PC Dual 3.5mm Headset to RJ9/RJ10/RJ22 Phone Adapter

U10 Headset Adapter Cable RJ9 to QD Cord for Cisco IP Phone 68xx 78xx 88xx 89xx 99xx Series

MKJ Headset Adapter Cable - Compatible with Cisco Phones, RJ9 Headset Cord, U10 Compatible for 7841 7942G 8841 7931G 7821 7861 9951 9971

PIIHUSW Headset Buddy RJ9 4P4C Female to 3.5mm Male Cell Phone Adapter Cable for Cisco, Avaya Telephone 40cm

U10 Headset Adapter Cable Compatible Plantronics QD Quick Disconnect Headsets for Cisco Phone 68xx 78xx 88xx 89xx 99xx Series & Models 7960 7961 7962 7965 7970 7975

MAIRDI Telephone Headset with RJ9 Jack for Cisco Phone, Including 3.5mm Connector for Cell Phone PC Laptop, Binaural Office Headset with Microphone Noise Canceling for Call Center Landline Deskphone

MKJ Cisco Phone Headset Corded RJ9 Telephone Headset with Noise Cancelling Microphone for Cisco CP-7821 7841 7942G 7931G 7940 7941G 7945G 7960 7961G 7962G 7965G 7975G 8811 8841 8861 9951 9971