This Racor filter was standard equipment on many Catalinas over the years.
The filter itself features a unitized mounting bracket for mounting versatility, an in-head primer pump for quick fuel system priming, a sediment and water collection bowl (safe for inboard use), a vent plug to easily evacuate trapped air, and a 10 micron Aquabloc®II filter element which repels nearly 100% of all free water found in fuel. Be careful which filter you use. There are several replacement elements available that look identical. For example, there is what appears to be the same filter that only filters down to 30 microns. It leaves particles in the fuel that are too big and may clog the engine's filter. Another version filters to only 2 microns. This is filtering particles from the fuel that are so small it may clog almost immediately, leaving you without power soon after replacement.
Catalina Yachts began installing these filters in October of 1998. See below under "May we also suggest" for the appropriate fuel filter replacement as well as for upgrading to a metal bowl or to a complete new kit that includes a metal bowl.