Perko - Gas Tank Vent - Chrome Plated Brass - 1/2" Dia. - 0515DP4CHR. Chrome plated bronze with removable 30 mesh, monel wire screen flame arrester. Designed to meet the requirements of the USCG safety standards for gasoline fuel systems.. Features:. Size - 1/2" Diameter. Chrome Plated Bronze. Removable 30 Mesh Stainless Steel Wire Screen Flame Arrestor (for use with gasoline applications)