Computer-installed Bluetooth wireless connection to headphones/speakers; Upgrade the Bluetooth function of old computers/laptops to break space constraints Built-in ceramic antenna, barrier-free 5-10 meters long-distance transmission anti-interference ability, more stable signal Product name: Digital display Bluetooth adapter Bluetooth version: V5.0+ Frequency range: 2400-2483.5MHz Frequency response: 10Hz-20KHz Input parameters: DC 5V-500mA Host weight: about 68g Charging time: about 1 hour Interface type: AUX/RCA/USB/TF Effective distance: 10 meters without obstacles Battery capacity: 3.7V/400mAh lithium battery Signal-to-noise ratio: 90dB Peripheral support: U disk/TF card Bluetooth protocol: HFP/A2DP/AVRCP Format: MP3/WAV/WMA/APE/FLAC Product size: 100x54x33(mm) Colour:black Material:plastic Package Contents: 1 x Bluetooth receiver 2 x Audio cable 1 x USB charging cable 1 x Manual in English and Chinese 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.