http://www.labock.com/english/bpg.htmUm, the holy shit factor is pegged on this one.
How does it work? ---->
On the protective side, as a bullet strikes the acrylic (brittle, but very strong when compressed) outer layer, the acrylic is compressed, strengthens, and absorbs/distributes the bullet\'s energy. Simultaneously, the polycarbonate layer, which has flexible characteristics, stretches as it dissipates all the remaining bullet energy, and there is no full penetration. There is some "spider webbing" on the impact side, but the inside of the glass remains smooth and undamaged.
On the One Way side, the reverse occurs - The polycarbonate is compressed, and the acrylic is stretched. The bullet easily passes through the soft polycarbonate layer, and into the acrylic layer, which becomes weak as it is stretched. The bullet shatters the acrylic and continues onward, with negligible loss of velocity, and practically no deflection.