Holdding DS3231 AT24C32 IIC Module Precision Real Time Clock Memory Module Arduino/Precise Time Clock Module with a Temperature-compensated Crystal Oscillator Usually, you will get it actually in 9~19 days, If you are in the USA and the item is NOT Fulfilled by Amazon. the item will be sent to you by USPS with shipping information from China. The estimated delivery time offered by Amazon is not the real time. Your patience is highly appreciated. Hope you will receive your item soon and enjoy using it. Clock chip: high-precision clock chip DS3231 Memory chips: AT24C32 (storage capacity 32K) Clock Accuracy: within 0-40 C range, the accuracy 2ppm, the error was about 1 minute per year. Operating voltage: 3.3 - 5.5V