xxRangerxx,
There is another custom part/s to replace the standard Surefire MA02 A2 Aviator bulb, which has been discontinued for awhile now, and when you can find them, aren't cheap.
Tad Customs makes a bi-pin bulb adapter to replace the Surefire lamp assembly, and also sells extra bulbs for it. His bulbs seem extremely well-priced. The MSRP on the original Surefire lamp assembly was in the neighborhood of $25:
http://tadcustoms.com/a2-bi-pin-socket.htm
http://tadcustoms.com/xenon-bi-pin-bulb.htm
I have no experience with the Tad Customs set-up myself, as I have the earlier and discontinued (and very difficult to find on the CPF marketplace) Fivemega's strion bulb adapter.
I do have Koala's onion ring in my A2 Aviators, and recommend them highly. The original Surefire led ring usually produces a "cloverleaf" pattern, which can be eliminated by "sanding" the leds with a fine-grit something (I used a Scotch 3M sanding sponge), I would advise against doing that to the original led ring, as that would void the warranty if you every needed to send it in. I would advise taking out the original led ring - be careful not to mar the tiny brass screws (again, voiding the warranty) - and carefully store it in a protective container. I have found the blue "Blistex" container to be a great size, once you thoroughly wash all the crap out. Once you get the Koala onion ring, you can sand the individual 5mm leds to your heart's content, and of course you have to trim the leads to the proper length. 5mm leds tend to be cheap, and if Koala is still selling them, I would advise getting the complete selection. I also found some 265nm UV 5mm leds, just in case I ever need UV. One of my Aviators has 5mm red leds in it (Um, don't use that one much since I don't do nighttime surveillance), and one of them has Yuji hi-CRI "white" (actually more yellowish) leds. If you ever decide to get into rechargeable Li-ion cells (and Tad customs bulbs seems to offer various possible configurations) - there are two main rules: 1) Do not scrimp on either the quality of the Li-ion cells or the charger (and please read the complete 'dangers' postings in the "battery" section of this forum, and 2) do as much research as you can on CPF regarding which quality rechargeable Li-Ion cells will actually fit in the A2 Aviator. It is a notoriously tight fit, and most "protected" cells will not fit. I myself use AW IMR 16340 cells.
