I offer three widths of shoulder straps with options for foam thickness. from left to right.
2" wide-these are best on the small classic packs, the White Light/ White Heat, New Day Rising and the Higgs Boson. or any pack where you want the most freedom of movement. typically filled with 1/4" or 3/8" foam. this is the strap attached to the blue pack.
2 1/2" wide- go standard on all packs. they work on big packs to small climbing packs built with all round use in mind. don't climb vertical ground as well. 3/8" or 1/2" foam.
3" curved straps. these are for bigger packs, but can be used on smaller packs if desired. filled with 3/8" or 1/2" closed cell foam.