Pipercross Air Filter Cleaning Kit - Dirt Retention Oil Cleaner Additive C9000 Why Pipercross Pipercross has been making high performance air filters for the motor sport and domestic markets for over 25 years. Based in Northampton, England, Pipercross is situated in the country along with some of the biggest names in motorsport engine design and manufacture in the world. In these 25 years their high performance filters have helped many race teams win major championships on the British, European and World stage. The development work carried out whilst dealing with these teams has enabled them to produce some of the most technologically advanced filters on the market. Cleaning Kit The perfect solution for cleaning and prolonging the life of your Pipercross filter, each kit .