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; White; Round Socket Size:3.5mm; Handset Size:21*5*6cm/8.27*1.97*2.36L*W*H); Cable length:1M/3.28FT This phone handset has an answer button and a volume 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