lol spot the odd one out: Supra, Skyline R31 R32 R33, 200SX, Commodore VN.
That thing is old, so I dunno what its capable of. But the new one is pretty good. Basicly its used to optimise your air fuel ratio. I wouldnt bother with the old one though personally. Heres the new one:
The ONLY thing I've considered from Apexi is the RSM... Similar to a G-Tech and basically all the same features but looks so much cooler...