UL Subject 6500
Standard for Audio/Video and Musical Instrument Apparatus for Household, Commercial, and Similar General Use (Bulletin, 2/14/2000)
standard by Underwriters Laboratories, 02/14/2000
UL Subject 823
Standard for Electric Heaters for Use in Hazardous (Classified) Locations (Bulletin, 2/11/2000)
standard by Underwriters Laboratories, 02/11/2000