BLS-B20 is a dual interface audio output household Bluetooth audio receiver that supports TF card, USB flash drive playback, hands-free calls, NFC connection. It uses an industrial grade power isolation module to solve noise interference This product is connected to your speaker (3.5 or RCA) through an audio interface (3.5 and RCA) Then, instantly turn your regular speaker into a Bluetooth speaker. The product has a compact and fashionable appearance, which is easy to handle Convenient to pair with products through Bluetooth devices (mobile phones, tablets, etc.), allowing you to enjoy anytime Music feast brought by Bluetooth transmission. Product specifications Product model: BLS-B20 Supported devices: supports connection between two mobile phones Bluetooth version: 5.0 Output interface: 3.5mm stereo RCA left and right channels Function introduction: TF, USB flash drive, hands-free call, NFC connection Bluetooth protocols: AVRCP, A2DP Frequency range: 2400-2483.5MHz Frequency response: 20Hz-20kHz Output power: 28mW RL=16 Signal to noise ratio: 90dB Total harmonic distortion: 0.1% Supports and AAC Forward transmission distance: 10 meters Supports Micro-USB interface 5V power supply size: 80 x 59 x 25mm Material: Plastic colour: Black Package Contents: 1 x Bluetooth Receiver 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.