This method has the benefit of not needing a clean room. RLGs require accurate machining, use of precision mirrors, and assembly under clean room conditions. SNOLAB is the world's deepest operational clean room facility. An alternative clean room mat is one made from polymeric material. Later that day, a fire engine arrived to clean Room 3 and the surrounding area. Another is somFree, which is a clean room design of IBM SOM, and binary compatible. Other applications include high precision assembly operations in a clean room for electronic components. The Eiconjet software was also developed in-house as a Clean Room design. To develop a legal BIOS, Phoenix used a clean room design. Application areas are i.e. Heat, clean room and refrigeration technology. One approach to doing so is clean room design. The Surface Assembly Laboratory (SAL) is a 780 square-foot laboratory with a class-1000 clean room. Clean room design is usually employed as best practice, but not strictly required by law. A single, "The Clean Room", was released on 27 April 2018.