These were in the tail of the BD01 and I asked him to sell it as an item.
No rattling of 18650 cells when used in a 26650 space.
And while changing the cells they can be hung around a finger easy, so they work easier then the normal tubes.
I use mine all the time and the question or remarks about rattling cells comes up pretty often so instead of finding proper sized o rings now Simon has solved it for us!
yeah and in a lot of 26650 lights they can be put over the spring in the tail to have them ready without taing space (I have a little box with those plastic tubes to hold a 18650 so these are taking space when not in use.
These nifty rings solved all the sissues I had with those tubes.
Hahaha there was a thread about grease for threads and Super-Lube is what I wanted
Could not find it at the China shops but super + lube as search terms did brought up several hits on the department you refer to.
I ordered a set of big c++krings for very little and use them for my Uniquefire 1401 (that has a round section in the middle a bit wider then the rest of the head now with those big rubber rings it stays how I put it down)
So lol I actually use those things for flashlights