Composite metal foam armor

I'm curious to know the thickness of this test plate. A quick look at wiki yielded this:

(https://en.wikipedia.org/wiki/Metal_foam)

Composite metal foam (CMF) is formed from hollow beads of one metal within a solid matrix of another, such as steel within aluminium, show 5 to 6 times greater strength to density ratio and more than 7 times greater energy absorption than previous metal foams.[15]

A plate less than one inch thick has enough resistance to turn a .30-06 Springfield standard-issue M2 armor piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with twice the resistance to fire and heat as the plain metals.[16][17] Another study testing CMF's resistance to .50 calibre rounds found that CMF could stop such rounds at less than half the weight of rolled homogeneous armour.[18]

CMF can replace rolled steel armor with the same protection for one-third the weight. It can block fragments and the shock waves that are responsible for brain injuries. Stainless steel CMF can block blast pressure and fragmentation at 5,000 feet per second from high explosive incendiary (HEI) rounds that detonate 18 inches from the shield. Steel CMF plates (9.5 mm or 16.75 mm thick) were placed 18 inches from the strikeplate held up against the wave of blast pressure and against the copper and steel fragments created by a 23×152 mm HEI round (as in anti-aircraft weapons) as well as a 2.3mm aluminium strikeplate

Composite metal foam armor - GIF