The PSR PAIR Air Injection Block Off Plates allow the elimination of fresh air injection into the exhaust system of your motorcycle with a simple to install and attractive package. Elimination of fresh air injection on modified sportbikes is necessary because it can cause backfires in the headpipes and muffler due to unburnt fuel from modified fuel mapping combined with additional oxygen spontaneously combusting in a high heat environment. The PSR PAIR Air Injection Block Off Plates will stop the annoying and possibly damaging backfires from occurring while allowing you to remove a few pounds in associated valves and hoses from your motorcycle. On late model EFI bikes with O2 sensors, especially when using a Dynojet Power Commander V with the Autotune feature, the air injection system must be blocked as it will introduce additional oxygen into the system which will skew the O2 sensor values and make it impossible to get a correct tune. All PSR PAIR Air Injection Block Off Plates kits include all the necessary block off plates and a cap for the airbox.