This product is a 4-digit electronic clock kit that requires self-welding and assembly. It is designed for installation and educational purposes by electronics enthusiasts and vocational schools. The microcontroller program has been pre-programmed, and no electronic version of the software will be provided. Power supply: DC 3.7V–5.5V Special note: For extended use, it is recommended to use a DC power supply. Using 3 AA batteries may result in faster power consumption and is not ideal for long-term operation. Features: 1. Displays current time in hours and minutes. 2. Independent adjustment for hours and minutes. 3. Second correction function. 4. Clock speed fine-tuning with 0–9 adjustable levels (default at level 5). 5. Dual alarm function with independent alarm on/off settings. 6. Hourly chime function that can be enabled or disabled. 7. Includes battery backup interface to maintain time during power loss. A voltage above 3V is required; compatible with two or three AA batteries or mobile phone batteries. 8. Alarm duration can be set from 1 to 99 minutes. 9. Stopwatch function with start, pause, and reset capabilities. 10. Counter function to record button presses or external pulse signals. Material: Plastic Color: As shown Size: Approximately 53 x 40mm Package Contents: 1 x Electronic Clock DIY Kit Note: The package includes only the items listed above. Other accessories are not included. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1–3 cm.