IS Icstation 0.56" C51 4 Bits Digital Electronic Clock Kit Soldering Practice AT89C2051 Circuit Board DIY Learning Kits These are digital clock DIY soldering project, need users to finish the assemble process, and know the basic soldering skills of electronic components, PCB with large solder joint and pre-marked electronic components name, enable the assemble and soldering process easier for DIY beginners, and science school electronic learning projects. Military grade FR-4 PCB board, thinkness 1.2mm/0.05", size 52x42mm/2.08"x1.68"(L*W), equipped with STC11F02E master chip, 4 digits 0.56" red LED module, 24 hour display format. DC 5.5*2.1 power port with 3V-6V power supply, come along with a 3.5mm USB power cable, plug in the USB charger to use, easier to get the power supply support. Accurate travel time, the error range 1 sec every 24 hours. It can be enabled hourly chime; Twice alarm clock setting. Please check the instruction in the description part. Please view and download English user manual in the Product Information - Technical Specification - Installation Manual [pdf ]. All messages will be replied within 12 hours as Technical Support. Clock DIY kits are 24 hour display format, accurate travel time, the error range 1 sec every 24 hours, supporting seconds correction, hourly chime function and twice alarm clock setting. Use DC5.5*2.1 power port with 3V - 6V power supply, come along with a 3.5mm USB power cable, plug in the USB charger to use, easier to get the power supply support. It will display 12:59 when Power-on, while isnormal interface (&#034;hours: minutes&#034;).The both channels of alarm clock are opened. At the same time, the first alarm clock has been set at 13:01, the second alarm clock has been set at 13:02. After power on, short press S2. The display of digital tube will switch between &#034;hours: minutes&#034; and &#034;minutes: seconds&#034;; Long press S1 to enter the system Settings menu,there are A, B, C, D, E, F, G, H, I sub-menu. Short press S1 sub-menu plus increase by degrees, finally back to the normal interface.