Product Material: Electronic material Size: 38mm (length) * 22mm (width) * 14mm (height) Working voltage: 3.3--5.5V Clock chip: high precision Clock chip DS3231 Clock accuracy: In the range of 0-40, the accuracy is 2ppm and the annual error is about 1 minute With 2 calendar alarm clocks Programmable square wave output Real-time clock generates seconds, Minutes, hours, day of the week, date, month and year and provides leap year compensation with a validity period of up to 2100Built-in temperature sensor in the chip with an accuracy of 3Memory chip: AT24C32 (storage capacity 32K)IIC bus interface, the maximum transmission speed is 400KHz (at a working voltage of 5V)Other IIC devices can be cascaded, the 24C32 address can be changed by short-circuiting A0/A1/A2, the default address is 0x57With CR2032 batteryWiring instructions (take Arduino uno r3 as an example):SCLA5SDAA4VCC5VGNDGNDPacking method: individual antistatic packagingQuantity: 3 Piece Set Package Contents: 3 * 3 Piece Set IIC Modules 1. Real-time Clock ChipDS3231 AT24C32 is used as a real-time clock chip that keeps time even when the main power is off (using a battery).2. Full Clock CalendarFunctionality including seconds, minutes, hours, day, date, month and year, with leap year compensation up to the year 2100.3. Extremely accurate: DS3231 memory chips - AT24C32, extremely accurate I2C real-time clock (RTC), with an integrated temperature-compensated crystal oscillator (TCXO) and crystal.4. Two Programs: Provides programmable time of day alarms and a calendar can be set to square wave output. Address and data are transmitted serially over a bi-directional I2C bus.5. Safe Enough: A precise temperature-compensated voltage reference and comparator circuit monitors the status of VCC to detect power failures and provide a reset output. It also monitors that the RST pin generates a P reset.