The Polini PWK intake kit has a diaphragm housing and spigot made of aluminum and is for use with PWK 24-28mm carburetors. The design and the accompanying membrane with a larger intake area, both durability and performance are increased compared to the original intake. The membrane in the kit, unlike the original membrane, is equipped with carbon fiber membrane blades, which are both stiffer and more durable than the original ones. At the same time, you don't risk damage to the engine if they break, which is a risk with the originals - especially on tuned engines.