it's not, but the purpose of the SS backplates is to help minimize the need for lead on a belt. In New England, depending on what you're diving, that can be well over 20lbs of lead and every little bit helps at that point. Personally if you are doing single tank in either the Pacific Northwest, or New England I think you're a fool for not getting a steel backplate, and preferably the DSS one with the weight plates. Put the bulk weight on the rig where it isn't going to move around and distribute the rest however you see fit. The weight pockets are even worse than a belt because they make the whole rig try to fall forward and make it especially awkward to try to swap tanks because of it