This is one I recently picked up used for my dogs. The weight range is listed as 40-70#. It fits my 60#, but goes a little farther back on his back than I'd like. It does not cinch down small enough for my 50# dog.

It has some wear on the bottom of the panniers on the ballistic nylon as shown in the pictures, but still has several years left in it.

This is a one-piece design. The pack is well padded.

Size is Small. Approximately 770 cubic inches (385 per side). Weight is 22.5 ounces on my scale.

$30 US + shipping.