Only yesterday, I tried an Ultrafire WF-501B with a head that wasn't completely straight on. It was stuck somehow, and I saw a small piece of O-ring coming out :green:
I just put the flashlight in a large glass of water and let it there for a while. After that, I thoroughly inspected it.
Not a single drop had come in.
Somehow, these Ultrafire WF-501B aren't so bad at all, IF you are lucky to catch a good batch.
I ordered the longer versions of the well-known "2X CR123" format, these can hold either 2X 18500 or 2X 18650 depending on the length. I ordered two each, when I get them in I'll share my thoughts about them.
Maybe they make for great hosts for a P91 with 2X 18650s?
Or for the G4 Sun module by FiveMega... a WA1111 in it, two 18650s in it and you'll have an immense light for very little money indeed
Timmo.