The exterior windows of Joe’s office and laboratory are made of 2-inch-thick laminated ballistic glass tinted to a blue-green hue. This highest level of protective glass allows 60 percent sunlight exposure and weighs 28 pounds per square foot. Inside, the glass surrounding the conference room is covered with a protective film that can withstand an attack from weapons such as a baseball bat, a chair or other heavy objects. Companies like 3M, ShatterGard, ACE/Security Laminates, V-Kool and Glass Security offer security film products.”]
Source: https://www.csoonline.com/article/2122889/secure-office-windows.html