Our mounting hardware options are all made from black oxy-coated steel. Our black oxy-coated steel allows us to insure extra duty strength as well as offer rust resistant charecteristics. The 2" drop hook allows for the base of a Solid Seat Insert to be recessed between the rails. The use of this Hook will result in a lower seat to floor height when used to mount a Solid Seat or an increased seat depth when used to mount a Solid Back