Features: Brand new and high quality Standard for RaspberryPi 40PIN GPIO Header, For RaspberryPi Series Boards, JetsonNano. Monitoring circuit with I2C communication automatic resets function. Incorporates DS3231SN High Precisions real time clock Chip, With Backup Battery Holder. Communication through I2C, programmable 16-bit self-increasing counter. On-board watchdogs warning LED, watchdogs overflows warning. Specifications: Material:PCB Communication interface: I2C Chip: DS3231SN Watchdogs chip: CH32V003 Power supply voltage: 5V Diameter of fixing hole: 3.0mm Size:Approx.65x30.5mm/2.56x1.2inch Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Development Board