Features: High-precision real-time clock module designed for RaspberryPi, it can also be used forArduino. The module itself can be adapte to 3.3V and 5V system, no level shifting required, which is super convenient Temperature range is -40C to +85C, timing accuracy is maintained at 5ppm (0.432 second/day). Digital temperature sensor with 3C accuracy. High-speed 400kHz I-two-C serial bus. Specifications: Name: High Precision Clock Module Material: Printed Circuit Board Size: Approx. 13.4x13.4mm/0.53x0.53 inch Other Features: Provides battery back-up for continuous timing Low power consumption Full clock-calendar functions include seconds, minutes, hours, day of the week, date, month and year, with leap-year compensation valid until 2100 Two calendar alarms 1Hz and 32.768kHz output Reset output and push-button debounce input +2.3V to +5.5V supply voltage 16-pin SO (300mil) package Note: Please allow 1-2cm errors due to manual measurement,pls make sure that you don'for t mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1 Piece Clock Module