General description The 2 in 1 NFC Bluetooth 5.3 Receiver and Transmitter is a versatile audio device that supports simultaneous connection to two Bluetooth playback devices. It features a Bluetooth 5.3 chip for enhanced compatibility and stability, making it an ideal choice for seamless audio streaming. Technical specifications Product model: M13 Pro Bluetooth version: V5.3 Supported protocol: RX: A2DP, AVRC; TX: A2DP Working frequency band: 2.402GHz - 2.480GHz Sensitivity: -85dBm Signal-to-noise ratio: ≥ 90dB Distortion: ≤ 0.1% Input interfaces: 3.5mm AUX, Optical, Coaxial, USB Output interfaces: 3.5mm AUX, Optical fiber Optical fiber input sampling rate: 32/44.1/48/96/192KHz, 24bit Supported audio formats: MP3, WAV, WMA, APE, FLAC, M4A, ALAC Screen size: 25x10mm Working current: < 40mA 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 (under barrier-free