Features:The module is a low cost, high precision I2C real time clock (RTC) with integrated temperature compensated crystal oscillator (TCXO) and crystal.The device includes a battery input port that maintains accurate timing when the mains supply is disconnected. Integrated crystal oscillator improves long-term accuracy of the device.Both commercial and industrial temperature ranges are being provide, adopting a 16-pin 300 mil SO package.This product is made of high quality ABS material, strong and durable.This clock module also has other functions that extend the additional features and options range of the system host.Specification:Material: ABSSize: Approx. 3.8x2.2x1.2cm or 1.50x0.87x0.47inchWorking Voltage: 3.3-5.5VClock Chip: High precision clock chipClock Accuracy: Under 0-40 accuracy 2ppm, annual error of about 1 minuteWith 2 calendar alarm clocksProgrammable square wave outputThe real-time clock generates seconds, minutes, hours, weeks, dates, months, and years, and provides leap year compensation that is valid until 2100The chip has its own temperature sensor with an accuracy of 3Memory Chip: AT24C32 (storage capacity 32K)IIC Bus Interface: Transmission speed 400KHz (when the working voltage is 5V)Battery: CR2032 (included)Package List:1 x Module.