Stage 1 Kits. Designed for motorcycles with a stock engine using the stock airbox, air filter, and stock or aftermarket pipe.
Stage 2 Kits. Designed for motorcycles with a stock or mildly modified engine using a well designed stock or aftermarket pipe with a modified airbox. Stage 2 kits are designed for applications where individual air filters cannot be installed.
Stage 3 Kits. Designed for motorcycles with stock or mildly modified engines using K&N individual air filters and a stock or aftermarket pipe. In most cases power increases of 10-15% can be achieved.