The Rockagator Ultralight Series are the perfect waterproof dry bag for those who make a point of counting the ounces when they get their gear ready to go.  These dry bags are perfect for camping and backpacking or any other application where lightweight gear is a premium.  You can stuff these with clothes, food or any other item that needs to stay dry for your adventure and when empty can easily be stowed without taking hardly any space in your pack.
These are fabricated out of lightweight but durable TPU and all of the seams are welded (not taped) so you can count on these being 100% waterproof.
Specs:
13 X 4 X 1 inches 
4.6 oz.
15L