Product name: Bluetooth audio adapter Bluetooth version: Bluetooth V5.2 Supported protocols: RX: A2DP AVRCP TX: A2DP Operating frequency band: 2.402GHz - 2.480GHz Power level: power level 2 (Class II) Signal to noise ratio: 99.3dB Distortion: 0.1% Support Dual stream (TX mode): support one to two connections Support Multipoint (RX mode): support (connect two mobile phones) CODEC TX: RX:AAC/ Working current: Less than 22MA Built in battery: 250MAH Charging current: about 200MA Charging duration: about 2 hours Endurance: RX 20H TX 12H Bluetooth distance: 10M (open place) Charging mode: USB TYPE-C 5V/0.5A Input/output connection mode: 3.5MM audio interface Compatible with: RX: mobile phone with Bluetooth function, , PC, PC TX: Bluetooth speaker or headset supporting A2DP protocol can be connected for use Size: 48 x 48 x 12MM Material: ABS colour: Black Package Contents: 1 x Bluetooth adapter 1 x type-C charging cable 1 x 3.5MM audio cable 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.