We ordered a Weld-B-Gone but I think they sent us a Kewler Kitz.
The kit has 2 O-rings, one about twice as thick as the other. More importantly, the male nipple (whoa!) - the outside threaded cylinder - is not threaded all the way. I'm thinking the Weld-B-Gone has it threaded all the way.
We could not get the valve to tighten in the keggle hole without using the thin O-ring on the inside. The connection does not leak but it is not tight and I'm a bit worried.
If I have this right then we could just order a threaded nipple from morebeer.com for a coupla bucks.