How do these things work or installed? Where can I get them, about how much would I expect to pay for a set for Douglas .190 12inchers?

 

4-wheel atv action used to have an advertisement for them, but i just looked and they dont now. if i remember correctly, they start at $20 each, and as for installing them, all you need to do is center them on your rim, use a mig/tig aluminum welder, and tack them. there are different ways to weld them, one is tacking in 4-10 places, and welding over the tacks. the other has to do with car bodywork, where you tack it in little places until the circle is complete, asto not heat the aluminum as much. but it looks better if you do a regular weld.
btw, you can also use oxy torch with it, but make sure you have an oxidizing flame, or you will certainly cut through the metal!

 

look in the james lucky cat., i thought about putting them on my wolverine but decided not to, thought they would hold mud and also make the rims a pain to clean.