Gutterglove Pro uses a high quality type 316 stainless steel micro-mesh and Gutterdome uses lower quality type 304 stainless steel micro-mesh (Type 304 is generally used for indoor applications). After 511 hours of salt spray testing, type 304 began to have problems as can be seen in the photos. NOTE: The type 316 mesh sample tested is from Gutterglove, Inc.’s Do-It-Yourself gutter guard, and the type 304 mesh tested is from another competing gutter guard and not Gutterdome. For full details, download the “GuttergoveVSGutterdome” PDF below.