K&N say …….
K&N® washable, reusable High-Flow Air Filters™ feature a state-of-the-art design of layered, oiled cotton media, engineered to improve airflow and capture contaminants—and designed to give you an increase in horsepower. Protect your engine with the filter that millions of drivers have trusted since 1969, from off-road to the on-ramp.
The last air filter you will ever need. K&N filters have a 1,000,000 mile guarantee, they just need cleaning and re-oiling periodically. K&N cotton gauze filters give virtually unrestricted air flow, whilst still providing very high levels of filtration to protect your engine. They are essential for fast road and competition applications. Cotton gauze elements require cleaning when they clog up, take a look at our range of K&N Service Products.
Full details at …… https://www.knfilters.com/air-filters
Note:- Due to more air being more freely getting to the carbs it is recommended that a richer needle is used. The original ACD needles in my HIF4s have been replaced with an AAA.
I have been pleased with my filters and recently cleaned them see …… https://mgb.tips/2020/05/31/cleaning-the-kn-air-filters-on-an-mgb/