Five section armor. It contains two shoulders, two elbows and back pieces. It can easily be inserted in most jackets that contain removable armor pockets. Made of triple density foam. This is the most commonly used armor in jackets. Most jackets sold online and in retail stores use similar armor.Compatible with most jackets that have removable triple density armor. It can be cut to fit size by scissor, if needed.Extremely light weight. All 5 pieces weight is less than 8oz on average.