【LED display】: The digital LED tube indicates the operating status and playing time. The blue LED has a warm feeling through the transparent housing and buttons. Depending on the size of the music, all states are clear at a glance. Exquisite design, car style, simple appearance. | 【Bluetooth 4.2】: Supports the Bluetooth stereo speaker function, that is, devices such as mobile phones can send music to the speaker (A2DP) via Bluetooth. Bluetooth based on the CLASS 2 power level, using the Bluetooth 4.2 specification, compatible with Bluetooth 3.0 and lower versions, the transmission speed can reach 3Mbit / s. | 【Playing TF Card / U Disk】: You can play music on the TF and U disc, the music format is: MP3, WMA, APE, FLAC, WAV (no license). FAT16, FAT32, ExFAT / Fat64 file system support. There is no limit to the number of files in a single directory, and the total amount of music files can be supported within 9999. | 【FM Radio and AUX Input】: Built-in FM radio function, reproduces a variety of speaker states and modifies the transmission language according to user needs. The frequency band is: 87MHZ ~ 108MHZ. Supports AUX input, that is, external audio sources can access the speakers through AUX and adjust the speaker volume. | 【Safety and Wide Application】: Anti-reverse energy design, even if the energy is reversed, the product will not be damaged. DC input, suitable for power supply from 9V to 12V. It is used in combination of home audio, car audio and multimedia computer audio, professional active audio, iPod audio, AV power amplifier, massage chair, electronic gifts, electronic toys, etc. Especially suitable for (loud) DIY enthusiast speakers.