actually, not true at all. the ergo backpack attaches via straps that are on the backpack -- there aren't any attachments on the carrier itself.
each corner of the backpack has a strap that goes around the strap of the carrier, and locks onto the locking device on the backpack. the top two are meant to go around the shoulder straps and the bottom two are meant to go around the webbing connecting the shoulder straps to the carrier.
so the backpack theoretically could be used with any ssc.
that said, reasonable people can certainly have differing opinions as to the usefulness of the bag in size and shape!
(although ergo would def. repair or replace any defective zipper issues).
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