Yes, our toughened glass bells are subjected to multiple thermal tests. The first begins with a series of thermal shocks test during which the glass dielectric shells are exposed to a series of hot and cold baths ensuring the bell has achieved the ideal state of toughened compression. In addition to the three thermal shock tests, each bell is exposed to, which exceed to two required by ANSI, the bell is also subjected to a heated soak test. The soak test exposes the toughened glass bells to an excessive (500 degrees Fahrenheit) and constant heat for 120 minutes. This rigorous test ensures that all nickel sulfide inclusions which are common in glass are detected and eliminated to ensure the shells will exceed the necessary shattering rates experienced while in service (typically less than 1 in 10,000).