PREV/VOL- long to decrease the volume; short in the USB/TF/Bluetooth/radio mode is the previous song/previous station PLAY/PAU in the USB/TF/Bluetooth mode, short for play/pause; long for mode switching, NEXT/VOL+ long to increase the volume; short in the USB/TF/Bluetooth/radio mode is song/next station MODE is the mode switch, a total of 5 modes (Bluetooth-TF-USB-FM-AUX). 5V-12V power supply Support folder selection and playback Support call/support recording (external recording). Recording needs to be operated in TF mode or USB mode. (Long the MODE button to start recording, long the MODE button again to cancel the recording and play the recording file; in the recording mode, a storage device U disk or TF card needs to be connected;) Support USB/TF/Bluetooth/Radio/AUX automatic switching Support power-off memory function: memorize songs and volume before power-off Product with power amplifier supports balanced output, stereo power 2 x 25W. Support MP3/WMA/WAV/APE/FLAC version of song decoding S ratio equal 70dB Audio frequency range: 87.5-108MHz size:93 x 36mm Material:plastic colour:black Package Contents: 4 x Decoder board 12 x 2P power cord 4 x 1P radio antenna 4 x remote control 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.