The original lens bezel is prone to break if tightened a bit to hard. This usually happens if the lens does not snap into place and you don't notice it while tightening.

In the original bezel there is a small groove for a rubber o-ring, which is not present in the replacement part i've used from thingiverse. Instead of adding it to the model, i've tried to print it with eSUN eTPU-95A which turned out great.

With my printing settings for that filament there is a bit of stringing and some blobs around the edges, but with a proper heat gun or a simple lighter these can easily be removed.

If you have better print settings, please share them with me, i would be happy to see improvements in the print quality.

The model fits perfectly to the flashlight and with the TPU used i don't worry about the missing o-ring. I'm less worried that this part may break this easily in the future.

The lens protector snaps right into place, you can just re-use it. Or as the original creator of this file mentioned, you can create your own replacement:

If you need to replace the lens as well it is a 52x1 mm clear lens. A possible source for this is recycling a CD Jewel Case.