Jetprime - Precision Control, Supreme Quality Jetprime PAIR Circuit Eliminator Cover for Aprilia RSV4 Tuono V4 The secondary air injection system (PAIR) routes fresh air from the airbox to the exhaust system in order to aid the combustion of unburned fuel in the exhaust. This system is designed to improve emissions on stock exhaust systems, but will cause exhaust popping and backfiring when you fit aftermarket exhausts. The CNC machined plate replaces the original cover and the rubber cap closes the hole in the filter box. eliminates exhaust popping noise on deceleration and backfiring typically associated with aftermarket exhausts achieves true A/F ratio for fuel tuning. A/F ratio measurements are reliable frees up engine space can improve throttle response when used with full aftermarket exhaust systems enables complete removal of the PAIR system, including the valve, the PAIR cover and the associated tubing the rubber caps are special heat resistant caps for high durability the block off plate is made by CNC machined 7075 aluminium included in PAIR Circuit Elimination Kit JPESKIT03 recommended for race use only Part No. JP ES RSV4 Model compatibility Aprilia RSV4 / RR / RF 2009 - 2022 Aprilia Tuono V4 / RR / Factory 2011 - 2022