WCB38Part DescriptionTypical Two-hole 8-1/2" X 3" Top Mounted Base with Standard 1-1/16" x 9/16" Holes. For 16 to 24 degree slopes Finish Anodized (M10-C22-A41) Includes (2) #17 X 1" S.S. TEK Screws, Neoprene Gasket