The screen that came with my 747 is simply a window screen material fitted to a frame that velcros to the radiator opening. It's finer than the steel mesh revealed by Tim, thus it catches bugs and other small particles considerably better. However, if you have more gravel on your local roads then Tim's set-up is certainly sturdier. I also use a velcro installed clear lexan panel over the
oil cooler. Acts as both a gravel shield and to help the
oil warm up faster (though not by much, I must admit).
-Dean