Was into it for a while for training and day walks but not getting used. (I'm either out with a full backpack or just a water bottle).
Two pocket sections, two water bottles ~600ml each and two little hip belt pockets. Comfortable and convenient, VGC. The 6 refers to six litre packing capacity. Easily fit a UL rain jacket, first aid, snacks and comms etc.
Asking $50 includes postage in Australia, guessing $15 to post it.
Cheers