VAPOR-LOK RECESSED CEILING SAUNA LIGHT - Unit can be installed in ceilings from 1/2" to 2 1/2" thick. Heavy duty mounting frame, full reflector design, UL & CUL listed for damp locations. Albalite glass. Metal Flange. Insulation must be 3" from housing. 7 3/4" outside diameter and is designed for new construction.