Vibrant's HD PowerFilter Fuel Filter Mounting Bracket is constructed from 6061 Billet Aluminum and comes with a hard Black Anodized finish.? The bracket features 4 holes for mounting and we recommend using any two of the four for a secure installation.?The inside holes at the bottom of the bracket are threaded for a M6 x 1 bolt with a maximum length of .45in (11.5mm).