Features: 1. This is a 24-hour digital circuit clock kit, using CD4518, CD4511, CD4081, CD4013, CD4060 and other chips. The circuit does not contain a microcontroller, so there is no program, and the hours, minutes, and seconds can be calibrated without an alarm function. 2. This kit mainly consists of a second signal generator, a counter, decoding display, and a timing circuit. The second pulse is accurately divided by a high-frequency signal generator to obtain a 1HZ square wave signal, which is more accurate in timing. 3. Can be used for teaching practical training welding, very suitable for DIY enthusiasts. 4. The product is made of , quality is guaranteed. Stable product performance, long service life. 5. The use of red digital tube, digital clear at a glance. color: Black Material: PCB circuit board + electronic components Note: This product is a DIY kit. It is not soldered and requires some hands-on skills. SIZE: 12.92CM x 7.86CM Package Contents: 1 x circuit board 1 set of electronic components (DIY parts) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.