The module itself can adapt to 3.3V and 5V system, no need for level conversion, which is super convenient. continuous timing battery . Complete clock calendar function includes second, , time, week, date, month, and year, and compensation until 2100. Low power consumption. Two calendar clock Reset output and anti-shake input Specification During -40 Degrees Celsius to + 85 Degrees Celsius temperature range, timing accuracy is +/-5 (+/-0.432sec/day). 1 Hz and 32.768 kHz output High speed (400 KHZ)I2C serial bus +2.3 V to + 5.5V power supply voltage Precision of digital temperature sensor is +/-3Degrees Celsius size:2.0*1.2CM/0.79*0.47 inch mateiral:CCL colour:BLACK packing:1* Real Time Clock Module Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.