Disassemble the tail cap, if it has a retaining ring you can remove it with snap ring plyers or the end of a binder clip. I used the binder clip because that’s what I had.
It should look something like this when done.
Remove the little “nub” (as some people call it) from the center of the rubber part of the button and replace it with the o-ring. It should look like this.
Reassemble everything without the “nub”.
I forget what size the o-ring is but I’ve heard the o-ring from inside of the valve caps on your tires works also.
Thank you very much for that. I had a pair of snap ring pliers and they didn’t work for this however the binder clip did! I was very nervous to do this mod and worried about ruining the threads. I think going slow and easy is the key. I did the mod and I must say the light is now amazing. So far no accidental activations. This is how the light should’ve came from the factory. IMO the light out of the box is dangerous and shouldn’t be carried without this mod or locking it out. Locking it out is a pain and if you use the light a lot so I’m glad I found this mod. A member on here hooked me up with some o rings. This is a great community!
3300k 7A has been on my belt since Sept 2019 when it came out. It’s been dropped on concrete and other hard surfaces. I finally put an o-ring in the tail cap. I like it even more.
I think it’s designed for XP-L HI, so SST-20 doesn’t look quite right. Also, SST-20 generally looks even more green when used in a reflector, and the tint bin probably isn’t better enough to fix that. Even the “good” bins look green at low levels, and a reflector makes the effect even stronger.
Of course, given how many times the FW3A has been changed, the FW1A also could have changed since the initial release.
I don’t know how the FW1A differs from the FW3A in the MCPCB shelf/cavity, but I used the Convoy S21A reflector. I was probably one of, if not the very first to convert an FW3A into a single emitter. . Currently with a sliced 4000k SST20 —Tiny, tiny hotspot. Looking to try a 3500k LH351 from Digikey next… Very happy with it overall.