If your machine is not running up to its potential, this kit is for you. This Stage 1 kit includes a new air filter, pre-filter, oil filter, and spark plugs. These simple to replace components can make a huge improvement in a machine that has been maintenance neglected. These filters are excellent quality replacements and Quad Logic approved. The spark plugs are genuine Champion plugs matched for your Sportsman 850. Works on all 2009-11 Sportsman 850 models. This kit includes: - Air Filter - Water Resistant Pre-filter for the air filter. - Oil Filter - Champion Spark Plugs (2) (REA8MCX)