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 high quality material, 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: 2 x circuit board 2 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.