Creative DIY electronic kit, using plug-in components, easy to make and use. USB powered 5V stable operation, easy to use. Red, yellow, and green LED display, indicating hours, minutes, and seconds respectively, supporting 6 color combinations. High precision 5PPM crystal oscillator, with small timing error and accurate and reliable travel time. The external dimensions are moderate, making it both a practical clock and a decoration. Kit Name: Binary Electronic Clock DIY Kits Working voltage: USB (5V) Display color: yellow, red, green Timing error:<1 second/day Dimensions: 130*100*35mm Color: Black Material: Acrylic+PCB Package Contents: 1 set of 4-Digit Electronic Clock 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.