No expensive gimmicky backpack to buy, just bring your own, stick it in and off you go.  Fits in any standard size backpacks.
Stand Alone rifle panel
NIJ III 0101.06 standard, protects you from M193 5.56, AK 7.62x39, and AK7.62x51(308)
63% lighter than the same size AR500 steel plates
Made of 100% UHMWPE, spalling resistant
Multi hit capable, advanced construction technique allows panel to maintain its integrity after being shot multiple times.
Largest coverage on the market
Fits almost every school backpack
Size is approx.10 inch x 15 inch x 0.85 inch
Weight: approx 4lb 9oz,  lighter than most of school text books
8 year warranty
Package includes: 1pc panel, backpack is not included.