On some modern engine and airbox designs, individual filters and proper jetting offer no performance improvement and compromise drivability; Stage 3 kits are not available in such cases, Designed for ATVs with stock or mildly modified engines using well-designed stock or aftermarket exhausts with a modified airbox and a stock or replacement air filter, For applications where individual air filters cannot be installed and where airbox modifications improve overall engine performance, Designed for ATVs with stock or mildly modified engines using individual air filters and a stock or aftermarket exhaust, Fully adjustable to allow for the use of well-designed aftermarket exhausts and stock replacement air filters, In most cases, power increases of 10-15%; drivability may be compromised in short-stroke high-rpm motors, Designed for ATVs with stock engines using the stock airbox, air filter and stock or aftermarket exhaust, Power increases of approximately 5% throughout the entire power range, A power increase of 8% can be achieved in most cases, Improve throttle response and drivability