The Polini PWK intake kit has an aluminum diaphragm housing and studs and is for use with PWK 24-28mm carburetors. The design and the included diaphragm with larger intake area, both durability and performance are increased compared to the original intake. The diaphragm in the kit, unlike the original diaphragm, is equipped with carbon fiber diaphragm blades that are both stiffer and more durable than the original. At the same time, you don't risk damaging the engine if they break, which is a risk with the original ones - especially on tuned engines. This kit also comes with a shorter intake port so it can be used with the reinforced Polini engine mount.