These are two genuine US military surplus items: the ALICE 2qt Canteen Pouch with the 2qt Collapsible Canteen.
This canteen is made from a semi-rigid heavy-duty plastic that will hold up over time, and is soft so that the canteen can collapse when empty. This canteen features the M-1 NBC screw-top lid that has a pass-through opening on the top, designed for use with a gas mask system where the canteen acts like a bladder.
The canteen pouch is Olive Drab (OD) Green in color and has two ALICE clips to attach to your pack, vest, or belt, and also have D-ring attachments on either side so the pouch can be used with a sling. These pouches are also lined with synthetic fur to keep your canteen cold (or hot). On the front is a small pocket for storing water purification tablets.
These canteens and pouches appear to be brand new, unissued items.