Voltage: 3.3-5V, Memory chips: AT24C32 (storage capacity 32K).The RTC maintains seconds, minutes, hours, day, date, month, and year incompatible withmation.About battery type: Battery is not included, you can use CR2032 or LIR2032 battery.The DS3231 is a low-cost, extremely accurate, I2C real time clock (RTC). The clock operates in either the 24-hour or 12-hour compatible withmat with an AM/PM indicator.Clock chip: high-precision clock chip DS3231.colour: blueMaterial: plastic+metalPackage Contents:6 x DS3231 Clock module (Battery is NOT included)Only the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.