PS -- Silverwind -- I just looked at GR Audio, and I'd pass. They don't tell you what's in the crossover, nor the crossover schematics. They only mention response levels. I'd go to www.madisound.com and look at the Audax AV kit if that's what you're into. Prices are about the same, and you'll *probably* get better sound. (There are no substitutes for hooking both sets to your system and testing them. Usually, that's too cost inefficient.)
EDIT -- Added the above advice for Silverwind.
The components are:
Alpha Core foil inductors, Links resistors, Axon caps with Sonicap by-pass
caps, and there is a Sonicap upgrade available.
And you put them together yourself, they send a diagram with them when you purchase. I searched high and low and could not find any negative comments on them.