Battery display allows you to know the headphone battery level at any time With vibration reminder function, you will not miss any important calls Easy-to-wear clip with functional clip for conveniently attaching Fineblue to your shirt Super long talk/play time, talk/play time up to 20 hours, standby time 180 hours Pair two phones at the same time and enjoy the comfort of Fineblue pairing two phones at the same time.Patented retractable cable technology allows you to retract the cable at the touch of a button after a call(Built-in cable) Works with any BT enabled phone Model: K55 Wearing type: In-ear Functions: Bluetooth 5.2, microphone, voice control, answering calls, song switching, multi-connection function Connectivity: Wireless Connection interface: Micro-USB Applications: mobile phones, computers, portable media players Talk time: 20 hours Music time: 20 hours Standby time: 180 hours (180 days without power) Bluetooth: Yes BT version: V5.2 BT mode: hands-free, earphones Material: PVC colour: Black Package Contents: 1 x Data cable 1 x Lavalier Bluetooth headset Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.