KYB is one of Japan's premier shock builders. Their AGX product provides adjustable dampening without having to move to a coil-over suspension. The AGX shocks are generally a little more firmly-damped than stock shocks, so they work great with moderate lowering springs.
Adjustment is with a knob on the top of the shock, both front and rear. Adjusting the rears will require removing the rear seats to access the adjustment knob.
Adjustment is four-way front and rear, and adjusts both rebound and compression simultaneously. Softest setting is slightly firmer than stock; hardest is very stiff.
Fits all 2002-07 WRX. (You'll want to use strut spacers on 2004-07 cars.) Complete set of four.