Specifications: This adapter converts a standard 3.5mm smartphone plug to an RJ9, RJ10, or RJ22 handset plug, allowing you to use your smartphone headset with compatible office phones. The adapter supports binaural audio output for stereo headsets, delivering sound to both ears. Converts 3.5mm OMTP smartphone plug to a single 4P4C RJ9/RJ10 handset/headset plug. Use your existing smartphone headset with your office phone's headset jack to save on additional accessories. This adapter is not compatible with Apple EarPods and other CTIA-based headsets. Performance is enhanced when used with an amplifier. For best results, connect to the headset jack on your phone; using the handset jack may cause audio distortion. Compatibility: List updated 3/1/17. Compatibility is not limited to the models listed. Incompatible Phones: Avaya 1100, 1200, 1600, 2000, 4600, and 9600 Series Cisco 7902, 7905, 7910, 7911, 7912, 7920, 7921 Nortel 1140T and Visa 350 Polycom Phones Shoretel IP 230 Uniden Dect2088, TRU9496 Western Electric 6250 Incompatible Headphones: Apple EarPods Compatible Phones: Aastra/Packet8/8x8 480e, 480i, 53i, 55i, 57i, 57iCT, 6753i, 6755i, 6757i, 9112i, 9133i, 9143i, 9480i Allworks 9212 AltiGen IP Phone 500, 510, 600, 705, 710, 720 Avaya 4500 Series IP ESI 48-Key IP Feature Phone and 48-Key Digital Feature Phone GE Model 2-9451 Inter-Tel Lucent 8410D Mitel IP 40XX, 41XX, 5000, 50XX, 5140, 52XX, 53XX, 5550 NEC Dterm Series E Norstar T7316E, M3904 Nortel IP 1120E IP, 1140E IP, 1150E IP, 1230, i2002, i2004 Nortel Meridian Norstar Northern Telecom Panasonic Hybrid Plantronics T10 Possum Sero Shoretel ShorePhone IP Models Siemens Splicecom PCS 520 Talkswitch IP Phone, TS-600 Toshiba 3COM 3102, 3103 Compatible Amplifiers: Plantronics S-12, M22, A20, MX10, TSB, AP15 Item Name: 3.5mm to RJ9 Cable Length: 20cm / 7.87 inches (Approx.) Notes: Due to differences in lighting and screen settings, the item's color may vary slightly from the images. Slight dimensional variations may occur due to manual measurement. Package Includes: 1 x 3.5mm to RJ9 Cable