sorry, wasn't exactly clear.

I mean this kind of bulb.



Interesting tib bit.
The 9006 is a low beam bulb
the 9005 is a high beam bulb.

The plugs are very similar. Basically, one is the male side and the other is more of the female side of the same plug design. Very very easy to modify and make the 9005 fit into the 9006 chassis plug. And the headlight housing socket is very similar too. Only have to trim a little bit off of one of the tabs to get it to fit properly.
The 9005 is technically 10 watts more than the 9006, but it is a common swap, and I personally have yet to see any adverse effects in the year I have been running this set up.

9006
55 watt
~1,000 lumens

9005
65 watt
~1,700

Very easy way to almost double the light output.