The construction of the Water Sack is identical to that of Ortlieb's dry bags with a
roll closure. The welded water valve in the base allows water to be
released at a controlled rate. The large roll closure opening allows easy
filling. The buckle straps can be used for hanging the Water Sack from a branch
or hook, and the black version is especially well suited as solar shower. The
Water Sack is made of tear-resistant waterproof fabric.