Heat shield mat - 4' X 4' reflective mat to protect surfaces from high temperatures near unit.
The heat shield mat must be used on surfaces within 3 feet of operating units when that surface must be protected. 
Because infrared is a light-source-heat,  only reflection is required to protect surfaces from damage.  
Mats can be used on walls and floors. 
If the mat bcomes non-reflective it must be replaced.