Whats the difference between 7440a and 7440? theyre both single filament bulbs and as far as i can tell have the same base.. so i dont get it? wahts the diff? can i use a 7440a bulb in a 7440 socket and vice versa?

 

The "a" stands for "amber" if I remember correctly.

 

SWEET thanks... so that means i can interchange a 7440a and 7440 bulb without fear of incompatibility.... thanks again!