Bulletproof glass, ballistic glass, transparent armor, or bullet-resistant glass is a strong and optically transparent material that is particularly resistant to penetration by projectiles. Like any other material, it is not completely impenetrable.Most bullet-resistant glass products are actually made of polycarbonate, acrylic, or glass-clad polycarbonate. The level of protection offered will depend on the material used, how it is manufactured, as well as its thickness. Bulletproof glass is used for windows in buildings that require such security, such as jewelry stores and embassies, bank counters, and windows in military and private vehicles.