Twin-Air Racing Air Filter 7232656. Racing Air Filter Foam (PowerFlow Kit) TwinAir The best filter in the world can not do its job if the air box seal is leaking. Twin Air’s Powerflow Kits provide a leak-proof, fool-proof fit with a sturdy, lightweight aluminum cage that replaces your thin plastic cage and an aluminum flange with a rubber seal that is bolted to your air box. 1x Twin-Air Air Filter. Product Type: Air Filter. You can send us a message by using the “Questions and answers” section towards the bottom of the page.