It's pretty clear in the description that it will only fit the 3/4 inch straps, which are probably the most common width of webbing on the shoulder and sternum straps of the current packs. No where does it make the claim to fit any specific pack, especially not an "older summer pack," whatever that is. You shouldn't one-star an item because you didn't make sure of a fit before you ordered it.

Hey dummy, I just bought a brand new Camelbak linchpin military style pack and it doesn't fit that one either. It should say something on the package. It's not unreasonable to assume that it would fit any Camelbak.