Constructed of corrosion resistant investment cast 316 stainless steel. Ring pivots out to open hatches, etc. and lays flush when not in use for a clean appearance. Installs with four #8 FH fasteners (not included). A 1-15/16" B 1-9/16" C 3/8" D 1/8" E 1-1/16" Fastener #8FH