The Hall-O is a Hall Effect Sensor PCB. It reacts to magnetic forces & is normally used as a non-contact distance measurement device. These sensors will also work as a 3D Printer endstop.
This item includes one (1) pre-assembled PCB, one (1) magnet and a one (1) 1m (39.37") cable.
You can view the schematic page of this PCB here. More information is also available on the RepRap Wiki.
This product designed by MaukCC.