Wausau
Window Protective System
The 4000i-DT Series of windows are high-performance, psychiatric-grade windows that are AAMA AW-120 rate, drop tested for interior human impacts of up to 2,000 foot-lbs., which is the equivalent of a 200 lb. person moving at 25 feet per second. For safety purposes, the windows feature anti-ligature sash corners and hardware, concealed hinges and tamper-resistant locks.
http://www.wausauwindow.com/products/index.cfm?page=productsDetail&seriesID=5&productID=162