This is an I2C interface expansion board with four 4-Pin I2C interfaces. Its main function is to expand the Crowtail Base shield I2C interface. When the I2C interfaces on the Base shield is not enough, use an i2c port to link the base shield, and the remaining three I2C interfaces can be used to connect the extra three I2C devices. The use and connection are very simple, a simple module may give you more possibilities for the project.
You can connect multiple I2C modules Access multiple external I2C modules, because each I2C address is not the same, you can work at the same time