Most coil part numbers indicate the make up of the coil. Usually the first
letter or two indicates the type of sleeve or the position of the lugs. The
next part of the number is the wire gauge, and the last part is the number
of turns. Because flipper coils have two windings, the part number
has two pairs of gauges and turns. For example a Williams chime coil
A2-26-1300 has 1,300 turns of #26 wire. Gottlieb is the exception
and their coil part numbers sadly do not give any such information.