NG 3500-G Nozzle Guard High Efficiency 10 Micron Spin-on Fuel Oil Filter keeps pumps & nozzles clean. UL Approved in Canada & USA. Robust shell is draw from extra thick steel and features a high burst pressure over 500 psi. Triple Corrosion Resistance (zinc-plated steel is coated inside and out with epoxy & the shell bottom is lined with a thick layer of plastic) eliminates rust. Meets UL spec DTOV2 for corrosion resistance. The spin-on design is quicker and easier to change. Gaskets don't stick to mounting heads. Flat-bottomed shell won't tip over and spill. Over 15% more filter media than competition, so lasts longer.