These Flat Tops are pieces of Flat Sheet metal which sits a few inches above the Carburetor Throats. These covers prevent water entering the carburetor throat. These covers must be used with the K&N Water-shield Filter Assemblies. These Water-shields should not be used on cars parked and/or driven outside in the rain. If you choose to drive your car on the street we recommend the K&N Water-shields which prevent rain/water entering the carburetors.