Platypus bags fit the threads on the full size Sawyer as well as many plastic drink bottles(most 2 liters will, but need a vent hole to work) and with a couple of extra parts they will also backfill Camelbaks with the Hydrolink adapter. Also possible to get a slightly smaller syringe from livestock stores, not much weight difference just smaller size.

"My message to my troops is if you see anybody carrying a gun on the streets of Milwaukee, we'll put them on the ground, take the gun away and then decide whether you have a right to carry it." - Milwaukee Police Chief Ed Flynn