Features: 1. This is a 24-hour digital circuit clock kit that uses CD4518, CD4511, CD4081, CD4013, CD4060, and other integrated circuits. The circuit does not include a microcontroller, so there is no programming involved, and the hours, minutes, and seconds can be calibrated. This kit does not have an alarm function. 2. The kit includes a second signal generator, counter, decoding display, and timing circuit. The second pulse is accurately divided from a high-frequency signal generator to produce a 1Hz square wave signal, providing precise timekeeping. 3. Suitable for educational training and soldering practice, ideal for DIY electronics enthusiasts. 4. Made from high-quality materials with reliable performance and long service life. 5. Features a red digital tube display for clear and easy-to-read numbers. Color: Black Material: PCB circuit board and electronic components Note: This product is a DIY kit. It is not pre-soldered and requires basic soldering skills and assembly. Size: 12.92 cm x 7.86 cm Package Contents: 1 x circuit board 1 set of electronic components (DIY parts) The package includes only the items listed above; other accessories are not included. Note: Lighting effects and display settings may cause slight variations in the color shown in the image compared to the actual product. Measurement error is +/- 1-3 cm.