BMC air filter induction kit ADDIA85-150Technical features DIA Diam. 1 (mm) 85 Diam. 2 (mm) 150 L1 (mm) 250 Thanks to the experience gained by BMC in creating supercharging dynamic airboxes, BMC developed the Direct Intake Airsystems (DIA), the "junior" filtration system. The philosophy of BMC's top range product, the Oval Trumpet Airbox (OTA) is behind the DIA, a system that, with its particular structure, ensures that aspirated air is carried to the engine at a higher speed and capacity