itself one layer of armor may be stacked such that the cellular structures 22 with composite inserts 70 inserted in close proximity with no filler therebewteen the sides 50 may be formed from multiple sides in stacked configuration as illustrated in the figures or one side cellular structure not illustrated extending past the inner cellular structure 40 the composite inserts 70 may be made of materials such as ceramic glass metal matrix ceramic matrix composite or any other types of composite materials known to provide high resistance to impact penetration while providing low weight particularly when compared to metal armor systems the surfaces of the composite inserts 70 may vary such as having convex or concave surfaces in addition to the other shapes described above the composite inserts 70 may be provided in square oval round or other shapes the cellular structures 22 may be formed in a variety of configurations but preferably use the cellular structures as described in u s patent application ser no 11 504 343 filed on aug 15 2006 such cellular structures minimize crack propagation from a projectile impact as described in u s application ser no 11 504 343 the cellular structures may be formed from individual fibers that extend approximately continuous throughout the cellular structure of course other fiber structures may be used without continuously extending fibers the filler within the polyhedron structure 20 is generally illustrated as 100 and is typically a ballistic foam or another type of lightweight filler material that is resistant to projectile penetration the filler 100 also helps to support.