Vibrant Performance Oil Restrictor Adapter Fittings allow you to limit oil flow to your turbo, minimizing the potential for oil seal damage. Each restrictor fitting kit includes a pair of threaded jets (with openings measuring 0.030 in. and 0.045 in.) that thread into the opening on the Male AN Flare end, allowing for customized oil flow control. Without restrictors installed, the fitting opening measures 0.060 in..