This is a brand new PWK 39mm Keihin carburetor. This carb works great on any 2 stroke ATV or dirt bike from 250-500ccs. If you are an advanced rider this carb will feed the cylinder with a ton of fuel. It will create much more mid range & top end power compared to most stock carbs. I have one on my race Suzuki LT500R ATV & it makes a huge difference compared to the stock 38mm carb. I also have some killer jetting specs based on years of research with this carburetor. The specs do require buying a different slide and jetting but it makes a world of difference. This carb has basic jets in it, it is not pre jetted for any make or model. Thanks