The 20cm 3.5mm Omtp Smartphone Headset To 4p4c Rj9/rj10 Phone Adapter Cable Cord is an amazing adaptor that allows you to use your favorite smartphone headset with your for Aastra office phone. It converts the standard 3.5mm smartphone plug to an for Aastra RJ9, RJ10, or RJ22 handset plug, providing you with the convenience of using your smartphone headset for work.This adapter outputs binaural sound for stereo headsets, ensuring that you hear sound out of both ears. It is compatible with single 4P4C RJ9/RJ10 handset/headset plugs, making it versatile and suitable for various office phones. By using this adapter, you can save money by buying a smartphone headset or utilize your existing one with your office phone's headset jack.Please note that this adapter is not compatible with for Apple EarPods and other CTIA based headsets. It works best when paired with an amplifier. For optimal use, it is recommended to plug the adapter into the headset jack on your phone, as the handset jack may cause audio distortion.The 20cm 3.5mm Omtp Smartphone Headset To 4p4c Rj9/rj10 Phone Adapter Cable Cord is a reliable and convenient solution for using your smartphone headset with your for Aastra office phone. With its compatibility with various office phone models and its ability to provide stereo sound, this adapter is a must-have for anyone looking to enhance their office communication experience.Key Features:Converts 3.5mm smartphone plug to for Aastra RJ9, RJ10, or RJ22 handset plugOutputs binaural sound for stereo headsetsCompatible with single 4P4C RJ9/RJ10 handset/headset plugsAllows you to use your smartphone headset with your office phoneSaves money by using a smartphone headset or existing oneNot compatible with for Apple EarPods and other CTIA based headsetsWorks best when paired with an amplifierProvides optimal audio quality when plugged into the headset jack on your phone