The silica gel bar can be used with Silby to protect your baseball wood bat from moisture (wood bat weight increase) When used with Silvy, it can effectively reduce the humidity of wooden bats (weight increase) Made of non-woven fabric that is more durable than ordinary non-woven fabricWorks with regular bat cases but is recommended to be used with Silby Baseball Wood Bat Drying Film Cases. It may not fit a single bottle or especially slim fitting bat case.