The CRT particulate filter is a patented emission control technology that contains a Platinum catalyst and a particulate filter. It is designed for use with large diesel engines, particularly large trucks and buses.

The device is made up of two chambers. In the first chamber NO is oxidised to NO2 by a platinum catalyst. The second chamber uses NO2 to oxidise particulate material to CO2. The catalyst also converts CO and HC into CO2 and H2O.

The CRT filter is capable of converting greater than 90% of particulate materials, hydro-carbons and CO to water and CO2. NOx reductions are typically up to 10%. These improvements significantly reduce the tailpipe emissions from heavy vehicles.

Over 35,000 CRT filters have been fitted on most major heavy duty diesel (HDD) engines in Europe, the US and Japan. It is the most widely used filter system for HDD engines and there are literally hundreds of millions of miles of service and durability on CRT filters.