The serial number can be found on the label on the back side of the machine. LBP654Cdw LBP612Cdw The serial number for both models is a four letter prefix followed by six numbers.
*6 The following custom sizes are available. LBP654Cdw : 4" x 5 7/8" (100 x 148 mm) to 8 1/2" x 14" (215.9 x 355.6 mm) LBP612Cdw: 3" x 5" (76.2 x 127 mm) to 8 1/2" x 14" (215.9 x 355.6 mm)