8 inch diameter, 14 inch tall funnel is D-shaped to combat swirling, while a lip at the top helps to reduce spilling. Funnel outlet is small enough to fit the "unleaded gasoline only" fillers on late-model production vehicles. We recommend adding a 115 Micron Funnel Filter Screen (Part No. 2575, sold separately) to your funnel to keep contaminants our of your fuel.