Byrna Shield Armor Plate Resistant Backpack Insert - 11"x14"As easy to insert into a standard sized student backpack as a school notebook, Byrna Shield Backpack Body Armor is a thin, lightweight (14 oz.), flexible Level IIIA rated ballistic plate. It can withstand up to 6 hits from . 44 magnum bullets with velocities up to 1,464 feet per second. For the price of a pair of sneakers parents can have peace of mind, knowing theyre giving their children a chance when the unthinkable happens, and avoid the high cost