Features: Perfect for electronics enthusiasts and hobbyists who enjoy building and assembling their own gadget. This kits provides a fun and rewarding experience for both beginners and advanced users. Whether it's in your living room, office, or workshop, this DIY clock will be addition to any space. Showcase your creativity and showcase your love for retrotechnology. 89C2051 digital clock kits, the control chip adopts AT89C2051, and the digital tube adopts three two-bit red common-anode LED digital tubes, with clear display and high brightness. Because it is a scannings display modes, the display brightness can be changed by changing the resistance value of R4R10. S1button is used to calibrate thetime, press and hold it for more than2 seconds to enter the calibration time state and exit, and quick touchs is used to adjust thetime values. A 3Vbackup battery is added to this circuit. In case of power failure, AT89C2051 uses thebackup battery to supply power, and the clocks will not stop, but the digital tube will not display, and it will be used asbackup power after incomingscall. Specifications: Material:Electronic Component Size:As Picture Shown Part Number:AT89C2051 Working voltage: DC5V-12V Package Includes: 1 Set LED Electronic Clock note: ①.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. ②.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings.