A must have for the Claymore RDA but while the build quality of the RDA itself is top notch this kit needs work.
I'd still recommend buying it, especially if you plan to use larger coils with the RDA. Can be fixed up in two minutes.
Like others have said the o-ring on the drip tip doesn't fit properly but just swap it with the spare that comes with the RDA itself and it's fine.
You might want to sand the rough edge of the 510 socket but it's not necessary.