My Mini Velocity clone is great for the 8 bucks or so I paid for it. The two bottom original o-rings are perfect, but I did have to replace the upper o ring to get more friction on the adjustment, the original was "non functional" is was so small. This happens allot with the cheap clones and having a bunch of spare o=rings is easy after you have bought enough of them. And it needed a complete tear down of the center post to get all the machine oil out from under it. Other than those minor things, its now a great RDA and I`m busy figuring out the best coils to put in it. Fortunately, putting coils in it is easy peazy.