Factory Glazed StormPro 320 shields against flying debris and helps ensure safety of occupants in safe rooms and storm shelters of small business or residential homes during tornadoes and other extreme windstorm events. Optionally available, factory-installed 10 x 10 in. tornado-resistant glass kit enables occupants to safely see if storm has passed. Tornado-resistant glazing is UL-tested as well as classified to FEMA 320 guidelines and ICC 500 standards.