4 digit clock kit for hands on building You solder and assemble it yourself It is ideal for electronics enthusiasts and large vocational electronics schools for installation and study Firmware The microcontroller program has been tested No firmware file will be provided Power and use For reliable long term use a DC power supply is recommended Three AA batteries drain quickly and are not suitable for long term operation Power range DC 3.7 to 5.5 V Key benefits - Hands on electronics project that builds soldering and assembly skills - Compact design suitable for classroom or maker space - Pre tested firmware provides consistent timekeeping and behavior - Compatible with standard DC power supplies reducing battery maintenance Applications and scenarios - Home hobby project to learn electronics - Classroom lab in electronics or engineering programs - Demonstration or prototype in a workshop or maker space Why choose this kit It delivers a real working 4 digit display with clear learning outcomes and dependable performance, supported by validated firmware and a straightforward power setup