The Radar is a technological device used by Mama's and Sisters, possibly created by the "Demons". The radar can locate and show where people are through the transmitters even at long distances. However, the radar can not identify who the people are.
Description
In general, the radar resembles a watch, being in a circular form with a cover, which protects the glass part of the radar. On every radar, there are marked designs, which indicates where the transmitter holder is, as quoted by Sister Krone.
Users
Three named people have been seen using the device throughout the series:
It is also further implied that all the other Mama's and Sisters in the other plants at the Grace Field House also use the device to locate the location of the orphans.
Gallery
Isabella's radar
Radar in Chapter 21.