The document describes a product with certain features and characteristics. The product has features such as X and characteristics such as Y, which can meet certain needs.
This manual covers the MK-F21D MP3 player’s specifications, hardware layout, installation steps and system requirements. It provides detailed instructions for powering on, adjusting volume, navigating menus, playing music, recording, FM radio, and using the A‑B loop function.
Additional sections describe battery handling, SD/MMC card usage, USB data transfer, software driver installation, maintenance tips and troubleshooting procedures, including emergency handling and service contact information. This manual is written in Chinese.
| Weight | ≈50 g |
|---|---|
| Dimensions (W × D × H) | 93 mm × 38 mm × 21 mm |
| Power Supply | DC 1.2 V rechargeable battery or DC 1.5 V (AA) |
| FM Reception Range | 88‑108 MHz |
| Frequency Response | 40 Hz – 20 kHz (+0 dB, –6 dB) |
| Output Power | 4.45 mW + 4.45 mV into 32 Ω (3.5 mm jack) |
| Playback Time (alkaline battery) | ≈10 hours |
| Supported Sample Rates | 32 kHz, 44.1 kHz, 48 kHz |
| Supported Bitrates | 8 kbps – 320 kbps (recommended 128 kbps) |
Press the power button for about three seconds; the screen will appear when turning on and the device powers down after three seconds when turning off.
The player can use a rechargeable battery, and it will charge automatically when connected to a computer’s USB port.
Insert the battery with the positive (+) side facing up; ensure it is seated correctly before closing the battery cover.