These are the metal strips that run between each of the bed boards. They are made of high quality cold rolled steel, and are available in polished or unpolished stainless steel. All of these bed strips are 1 1/2 wide and 18 gauge thick. Brothers suggests buying the pre-drilled strips, which are pre-punched with square holes, to save you time and effort. It also makes installation a lot easier! We do carry strips that are not punched. Un-punched strips are sold individually. 1947-50 Stepsides require 8 strips, 1951-72 stepsides require 7 strips, 1958-59 fleetsides require 7 strips on longbeds and 8 strips on shortbeds, 1960-72 fleetsides require 7 strips for longbeds and only 4 strips for shortbeds.