I have GE #63s in my bike('48 takes two). I have the original rear lens but it does not show the number on it as the headlight lens does. The GE spec book shows the #63 to be as follows: G-6 style base, 7volt, 3 CP, .63 amps and a single filament. Somewhere I have the specs for the headlight bulb but in a different book(older).