Xerosox Waterproof Cast Cover - Half Arm Small 7½ - 9½ in #HA-13

This works well for what it is intended to do. It actually left bruises on my son's arm from the tight suction created around the cast. It keeps your cast dry better than anything else we tried and does not leave baggy excess material draping off arm when wet.

Amazing how well it worked! Strongly suggest slipping a sock over the cast first. Allows sleeve to slip on more easily, and protects sleeve from rips and tears from rough edges of cast. We ripped and tore the first one. Used a sock, no problems with the second one. Saved our summer vacation, pool time, and made showers much less of a hassle.