The Product Acoustic Signature System ("PASS") is a non-intrusive, non-destructive acoustic detection device that is handheld and battery operated, making it highly portable. It is used fast, easy, and secure on sealed containers of various sizes ranging from 2 inches to 8 feet in diameter. This device detects submerged contraband or hidden objects or compartments, classifies material contents, exposes containers/commodities that are fraudulently labeled, flags containers with ”like” from “unlike” items, and determines container fill levels. It is mainly used at border crossings, security checkpoints, and high value locations.