Browning's VCI (Vapor Corrosion Inhibitor) gun sock seals out moisture. VCI penetrates into the smallest crevices where oils cannot reach, driving out moisture. Provides full protection by forming an enclosure around your firearm from muzzle to butt stock. The VCI sock, when used in a safe or cabinet, will offer additional protection to all metal items in the enclosed area. Vapor Corrosion Inhibitor (VCI) forms a protective vapor enclosure around the entire firearm, drawstring closure.