The PC Racing filter skins are one of the things we pack for every ride! it makes cleaning air filters 10x easier. we use them on our cry 450x Baja bikes as well as our gas gas 300 xc enduro bike. My favorite part about these skins is that you can stack them up on your air filter for multi-day rides. so after a long day of riding, all we have to is pop the seat off and peel a skin off and we are ready to ride again! another great PC racing product is the stainless steel reusable oil filter for the CRF 450x. this is a great way to increase oil flow through the motor and they are very easy to pull out, clean and throw them back in! overall this is a great company with very well thought out products built to make riders lives easier and bikes run better!(attached is a picture of a air filter with double filter skins being put in maxs bike during our last ride to Cabo)