durable. Fine workmanship and perfect style. Bluetooth version: Bluetooth V5.3 Supported protocols: RX: A2DP AVRC TX: A2DP Working frequency band: 2.402GHz -2.480GHz Power level: Power level 2 (Class II) Sensitivity: -85dBm Less than 0.1%BER Signal-to-noise ratio: 90dB Distortion: 0.1% Interface Type Input: 3.5mm AUX+RCA+Optical+Coaxial+USB Output: 3.5mm AUX+RCA Optical fiber parameters: supports optical fiber input, sampling rate supports 32/44.1/48/96/192KHz, 24bit Supported formats: MP3/WAV/WMA/APE/FLAC/M4A/ALAC/ Screen size: 25x10mm LED Working current: Less than40mA Built-in battery: 3.7V/1000mAh (3.7W) Charging current: about 1000mA Charging time: about 1.5 hours Battery life: RX about 10H, TX about 10-12H Bluetooth distance: 10-20M (without barriers) Charging : Type-C 5V/1000mA Compatible devices: Suitable for Android and IOS mobile phones and PADs, active speakers, power amplifiers and Bluetooth speakers or headphone connections that support A2DP/protocol Material: abs colour: Black Package Contents: 1 x Bluetooth adapter host 1 x Type-C charging cable 1PCS x 3.5mm audio cable 1 x Red and white RCA lotus 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.