The factory blow off valve in the Caliber SRT-4 acts as a way to limit boost. Remove the factory BOV, and install our pressure stopper onto the compressor housing of your stock turbo. Install the AGP aluminum hard pipe with Turbo XS RFL blow off valve, it's as simple as that! This kit includes the hard pipe, silicone hump hose, pressure stopper, hose clamps, vacuum lines, zip ties, fittings, and Genuine Turbo XS RFL BOV.