The adjustment is the knob on top of the unit. There is an arrow on top of the coilovers that shows the direction to turn ther knob to firm or soften the damping. You can go to BC Racing web site for more information on these. My son has these BC /BR coilovers on his 05 WRX and they have been very reliable and easy to adjust. He autocrosses the car and does very well within his class. The BC Racing coilovers get some flack on the web sites , but for the money they are an upgrade from most springs and strut set ups like Tokiko, Eibach etc. We had Mach5 springs and Tokiko struts on the 05 WRX before the coilovers and the coilovers are way better.