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DS3231 AT24C32 IIC RTC Module Clock Timer Memory Module Beats Replace DS1307 I2C RTC Board (Batteries not Included) + 20 PCS Male to Female Jumper Wire Cable at Amazon.com
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Amazon.com: Clock Module, 4pcs DS3231 High Precision RTC Real Time Clock Module Memory Module RTC adapted to 3.3 V and 5 V System for Raspberry Pi with Battery : Electronics
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