Signal stabilizer 15 meters barrier -free transmission signal stable, zero delay without stuttering, applicable car/office/entertainment and other household occasions Supports TF card plug-and-play. Insert TF card for playback. Built-in smart decoder can directly play TF card music. Supports multiple formats (MP3/WAV) Upgrade devices without Bluetooth to a Bluetooth LED digital display Bluetooth adapter High-definition LED digital display with real-time status display and cold light that is not dazzling. Equipped with Bluetooth 5.3 chip for better sound and more powerful performance Built-in 300 mAh lithium battery, continuous listening to songs, navigation and calls for about 8 hours. Four modes to meet your needs. One-touch switching between receiving/transmitting/FM/TF modes Bluetooth transmit power: 7dBm Output impedance: 32 Frequency response:20-20Khz Signal-to-noise ratio: 90db Microphone sensitivity:-42db Bluetooth receiving effective distance: 15M FM transmitting effective distance: 2M FM transmitting frequency: 87.5-108.0MHZ TF card playback: supports automatic power-off memory function, supports up to 32G Input parameters: 5V/2.1A Charging time: about 2 hours Listening time: about 6 hours Bluetooth transmit (TX), Bluetooth receive (RX), TF card playback Bluetooth version 5.3V Applicability: computers, , projectors (transmitting mode)/speakers, headphones, vehicles (receiving mode) AUX interface Built-in battery 300MAH, with protective plate Colour:As Shown Material:ABS Package Contents: 1 x Bluetooth Transmitter Receiver Only the above package content, other products are not included.