SPEEDFACTORY RACING BILLET ALUMINUM B-SERIES BLOCK OFF PLUG - BLACKThe SpeedFactory Billet B Series Breather Port Plug was designed specifically for use on Honda Acura B Series engines to block off the OEM "black box" breather port. This allows you to utilize the (2) M28 threaded holes on the back of the engine block for your aftermarket oil catch can breather system, resulting in the proper crankcase ventilation your high performance engine needs. Precision CNC machined from 6061 T6 billet aluminum Black Anodized