Plantronics P/N #26716-01 Quick Disconnect Cords (QD Cords) to attach Plantronics "H" series Headsets to Plantronics M10, M12, M22 & MX10 Amplifiers.

ALSO fits Cisco IP Phones:

Cisco 6921, 6941, 6945, 6961, 7931G, 7940, 7941, 7942, 7945, 7960, 7961, 7962, 7965, 7970, 7971, 7975, 8941, 8945, 8961, 9951 & 9971