The meaning of Apple's charging cable is eight lines
Apple Fast charge line eight pins.
Apple does not have a 20w fast charge cable, only 18w, which has eight pins.
The 20w pin is leaky relative to the 18w pin. The stitches of genuine 20w have 8 stitches, 1 needle on each side and 6 in the middle.
20w Serial number At present, 20w has only 2 fountifiers, Celcon and Flextronics. Cercon (f16) 12-16 fixed code pmg9a Flextronics (c4h) 12-15 fixed code pf4m, 16-bit a or b, most a and a small b.