This is a complete billet anodized head breather kit for your stock OEM KLX110 cylinder head (also fits the TB V2 Race Head and the YX150/160 cylinder head). They help vent the extra pressure your big bore motor is producing. As an extra bonus, they look really nice and compliment any other billet covers you may have. These are a great upgrade and help with oil blowing out of your crankcase breather during motos.