Earldom M11 Bluetooth FM Transmitter version: V2.1 + EDR Supports USB Flash devices and Micro SD/TF cards Encourages WAV, WMA, and MP3 files Large 16-bit LCD screen for tracking data display The last frequency memory feature FM channels have a frequency range of 87.5 to 108 MHz (206 channels total). For optional digital sound output, an integrated equalizer For best results, use an infrared remote control. Encouragement USB power source 3.4A output Gray in color