O-rings for flashlight?

[divin'dog]

I've been reading where divers have been replacing o-rings on cheap ebay dive lights just to hedge against flooding. I bought one of those cheapie lights but cannot find o-rings to fit. Does not seem to be a standard size. I've looked online and in the big box stores. Nothing in the size I need...??

For those of you who have replaced your o-rings, were they standard size? If not, where did you buy them? Any particular type of rubber and durometer you would suggest?

Thanks in advance.

 

[redacted]

I've been reading where divers have been replacing o-rings on cheap ebay dive lights just to hedge against flooding. I bought one of those cheapie lights but cannot find o-rings to fit. Does not seem to be a standard size. I've looked online and in the big box stores. Nothing in the size I need...??

For those of you who have replaced your o-rings, were they standard size? If not, where did you buy them? Any particular type of rubber and durometer you would suggest?

Thanks in advance.

First off, don't try to choose a replacement o-ring based on the size of the Chinese o-ring you are replacing. They seem to favor using a smaller diameter (and softer - easily damaged) o-ring with a fatter cross-section and then stretching it to fit, somewhat. I measured the gland size and the cap size to choose a 2-018 for my Trustfire J1s. It also uses the 18350 battery so it might work fine on yours also. Be careful you don't lose the magnet in the switch ring. I used nitrile as it is lease expensive and adequate. Mine are duro 70 but a bit softer would be OK. The fit was a little tight so install the cap carefully.