Product Description: Supports MP3 playback, automatically plays when powered on, with a red LED indicating playback status. Supports U-disk (tested over 32G) and TF card (tested 16G) playback modes; the default mode is TF card when powered on. If the TF card is not present, it automatically switches to U-disk mode. If both devices are installed, you can manually set the playback mode; refer to the button function instructions. Button controls for track skipping, volume +/-, pause/play, and mode switching. Note: "Long press" duration is approximately 2 seconds. If using U-disk mode, a 5V power supply is recommended, as some U-disks do not support 3.7V power. Product Specifications Power Supply Range: 3.7 ~ 5.5V Product Size: 45mm * 36mm Exquisite double-board design with a copper surface for stable and reliable performance. Anti-static bag packaging to prevent damage due to static electricity during delivery. Material: metal Color: blue Package includes: 1 x Mp3 lossless decoder board Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowable measurement error is +/- 1-3 cm.