Highest precision clock module DS3231 <br />Note that Arduino board can also use this module <br />This module itself can suit the 3.3V and 5V systems, no need to convert the level, this is very easy! <br /><br />Product size: 14 x 14 x 12 mm <br /><br />Features:<br />1. From -40 ° C to + 85 ° C temperature range, timing accuracy is maintained at ± 5ppm (± 0.432 seconds / day)<br />2. Provide battery backup for continuous timing<br />3. Low power consumption <br />4. Device package and function compatible with DS3231<br />5. Complete calendar clock functions include seconds, minutes, hours, day, date, month and year time, and provide valid until 2100 LeapYear Compensation<br />6. Two calendar alarms<br />7. 1Hz and 32.768kHz output <br />8. Reset output and button debounce input <br />9. High-speed (400kHz) I2C serial bus<br />10. + 2.3V to + 5.5V supply voltage <br />11. Digital temperature sensor with an accuracy of ± 3 ° C <br />12. Operating temperature range: -40 ° C to + 85 ° C  <br />13. 16 Pin SO (300mil) package <br /><br />1 x Clock Module <br /><br /><img src="http://img6.eachbuyer.com/x9/p100/eb3744_1.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/eb3744_2.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/eb3744_3.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/eb3744_4.jpg" />                                                        <img src="http://img6.eachbuyer.com/x9/p100/eb3744_5.jpg" />