The PC-01 PCB displays the received weight on the 6digit display which is at the left corner of the board .The centre 5digit display shows the unit weight of a single piece the right 4Digit (also available in 5-digits)display shows the total number of pieces measured. The PC-01 PCB has only a simple diode. Shorting protection of reverse battery. Hence make doubly sure to connect the right battery polarity may damage the PCB permanently& carries no guarantee. Use of 0.5Amps fuse as protection is lightly recommended.