Volant Pro5 Cotton Gauze Air Filter Cleaner And DegreaserAir flow test have proven that cotton gauze filters flow much more air than paper element filters do. However, when they get dirty, they can clog up and limit air flow. This is one reason why you should clean your air filter with Volant's filter cleaner kit. The kit contains Volant's filter cleaner that loosens and removes dirt trapping capabilities. Volant's filter oil contains a blue dye to easily see where the oil has saturated into the filter,