Fresh air injected into the exhaust system on modified sportbikes can cause backfires in the headpipes and muffler due to improper fuel mixture. Block off plate install allows you to achieve optimum fuel/ air mixture when tuning and shave some weight off your motorcycle. These plates come in anodized black to further increase resistance to corrosion and longevity of the part. Each piece is inspected and laser etched with the Driven logo.; The most accurate way to tune your bike on the Dyno, the Driven Engine Block-Off Plate is a trouble-free way to eliminate unwanted air leaks These plates are made from high quality 6061 billet aluminum and anodized for corrosion resistance Machined then inspected to fit perfectly Great for helping to eliminate the popping common with aftermarket exhaust