Full Arm - XSmall Waterproof Cast Cover

This cast cover is completely watertight, keeping your bandages,
prosthetics, and casts dry. It is the only leg and arm cast protection
in the world with the patented vacuum seal to keep your bandage or
cast dry. It is so completely and totally waterproof, between the
waterproof fabric and the vacuum seal, that you can even dive off a
diving board, ride the ocean waves,or scuba dive and still have your
cast stay completely dry. Arm and Leg Cast Covers are designed to fit
snugly, especially the opening at the end of the cast cover where the
arm and leg cast covers must remain sealed. To create a good vacuum
seal the opening for your specific cast cover needs to be smaller than
your limb.  

ARM : 1. Measure from the tip of the middle finger to the top end of
the cast or prosthetic. If the cast goes above the elbow, follow the
bend of the arm. If the cast is close to the elbow then measure to
the mid bicep. Don't worry if the waterproof cast cover is too long.
The excess material of the cast sock will flatten down when the air is
pumped out. Measure on the skin above the cast, not on the cast
itself. Make sure that the cast cover is at least 2 inches longer
than the cast. 2. Measure the circumference of the arm just above the
cast or bandage (If the end of the cast is very close to the elbow,
measure mid bicep.)