Description:The RTC module is specifically designed for Raspberry Pi. It communicated with for Raspberry Pi through I2C bus. Features:Use Maxim DS1307 chipCan be operated by a shellSet a serial port connectorProgrammable square-wave output signalAutomatic Power-Fail Detect and Switch CircuitryProgrammable Square-Wave Output SignalPort:Raspberry Pi B module 2X13 connection portRaspberry Pi A+/B+/2 module 2X13 connection port2*5pin 2.54mm connectorSpecifications:Accuracy: 2ppm from 0C to +40CWorking Voltage: 5VBattery Backup Input for Continuous Time keepingReal-Time Clock Counts Seconds, Minutes,Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100Work Temperature: 0C to +70CTypical Application:Smart homeUtility Power MetersTelematicsColor: RedSize: Approx. 2.65 * 2.27 cm / 1.04 * 0.89 inPackage Weight: About 5gPackage Included:1x RTC Module for Raspberry Pi (Not including battery.)