The green light is on/off means the user is available (Supports manually setting the green light is on/off to indicate you are idle). The red light flashing means there is an incoming call, and the red light is always on means the user is on a call, then people would not interrupt you. In addition, currently only the SFB(Skype for Business) VoIP Phone supports a yellow light, which means the user is walkaway. Compatibility - With 2.5mm jack, plug-and-play, compatible with Yealink devices: WH68, WH64, WH63 E2, WH62 wireless headsets, and MP50 USB teams phone. BLT60 synchronously displays the desk phone/softphone presence state, helps to boost productivity.Security Support Period：Until 31/12/2026 Easy to Use - Yealink BLT60 has 1.8m cord allows you to place wherever it's easily seen, such as the corner of desk or the PC monitor. When you're not at the table while the BLT60 turns red, you will know here comes a call even no bell reminder. Security Support Period：Until 31/12/2026