Designed with Bluetooth 5.1 chip for improved compatibility and stability. Bluetooth receiver (RX) and transmitter (TX) in one device. Equipped with HD LED digital display for clear visibility of working status and Bluetooth mode. Built-in decoder chip for enhanced bass effect; supports three-level gain adjustment. Upgraded NFC function for smartphone tap-to-pair connectivity. Bluetooth version: 5.1 Supported protocols: A2DP, AVRCP, HFP Operating frequency band: 2.402 GHz – 2.480 GHz Power class: Class II (Power Level 2) Sensitivity: -85 dBm (BER < 0.1%) Signal-to-noise ratio: 90 dB Total harmonic distortion: 0.1% Interface types: Input: 3.5 mm AUX, USB, TF card slot, 6.5 mm microphone input, digital optical fiber, digital coaxial Output: 3.5 mm AUX Supported audio formats: MP3, WAV, WMA, APE, FLAC, G.729, M4A, ALAC, DTS, MIDI, G.726 Built-in rechargeable battery: 3.7 V / 1200 mAh Charging current: up to 1000 mA Charging time: approximately 1.5 hours Battery life: up to 8 hours (RX mode), up to 8 hours (TX mode) Bluetooth range: up to 30 meters (in open space) Charging port: USB-C (5 V / 1 A) Compatible devices: smartphones, tablets, active speakers, power amplifiers, desktop computers, audio mixers, karaoke systems, etc. Product dimensions: 98 × 67 × 24.2 mm Color: Black Material: ABS plastic Package contents: 1 × Bluetooth adapter 1 × Infrared remote control 1 × USB-C charging cable 1 × RCA (red/white) audio cable 1 × 3.5 mm AUX audio cable 1 × English user manual Note: Actual product color may vary slightly due to lighting conditions and screen settings. Dimensions are subject to a tolerance of ±1–3 cm.