?1-Year Warranty & Compatibility Notes?: We offer 45 days money back & 1 year worry-free guarantee. NOT WORK FOR SMARTPHONES AND COMPUTERS. ONLY COMPATIBLE with some specific phone models listed in description (include but not limited). For other landline phones, please consult us for Compatibility Guide or Advice. ?Easy to Connect?: Plug and play, simple to use. It only takes 2 steps to use: Plug RJ9 Jack to the headset port of your phone; Connect QD Connector to your headset port. QD feature enables you to walk away from the desk without taking headset off and keeping call still remains. It's a practical and good companion for business, make your work easier. ?Super Long & Ultra Durable?: The length is 68 inches/5.7 feet (no stretched), 80 inches/6.7 feet (stretched out). This QD to RJ9 cable provides the rational length for connecting a QD headset to a landline phone and facilitates talking anytime. Coiled cable with spring wire design, free from knotting or twining, durable and strong. ?RJ9 Jack Telephone Compatibility?: This RJ9 headset adapter is compatible with Yealink T19P T20P T21P T22P T26P T28P T41P T23G T32G T40G T42G T48G T41S T42S T46S T48S Avaya 1608 1616 9608 9611G 9620 9630 9640 9641G 9650 J139 J169 GXP 1200 1400 1405 1610 1615 1620 1625 1630 2124 2140 2160 280 285 GXV 3005 3240 3275 Snom 300 320 360 710 821 870 Panasonic KX-T Series phones 7220 7330 7420 7433 7665 7740 Zultys ZIP 36G 37G 33i 35i AltiGen IP805 and more phones listed in description. ?Compatible with Plantronics QD Headsets?: This headset cable is compatible with All Plantronics Quick Disconnect (QD) headsets and other headsets with the same QD connector. Great headset cable replacement of Plantronics U10P-S/HIS Adapter 38099-01 cable. NOT for Jabra GN Headsets.