This is a retro mobile phone receiver that allows you to be more comfortable when answering calls. More suitable for people who communicate on the phone for a long time The Telephone Handset provides here,Color: Black; Round Socket Diameter: 3.5mm; Cable length: 1M/3.28FT;Handset Size:21*5.2*4cm/8.27*2.05*1.57L*W*H) This phone handset has an answer button button, you can adjust it according to your needs, with a 1-meter extension cable, you can easily answer calls Steps of intallation:1. When there is an call on the mobile phone, use the Telephone Handset plug to point the hand socket;2. Press the answer key Only works with 3-channel 3.5mm audio socket,before purchasing, please confirm the size of plug