SPARK ARRESTOR REQUIREMENTS
USFS SPARK ARRESTOR GUIDE

USFS Rangers use the following procedures to inspect your spark arrester...

"Standard 5100-1c requires that each arrester shall be permanently marked with the model number and the manufacturer’s name or trademark. The model number must match exactly. The identification must be stamped in the metal body or on an attached metal plate. The words "Qualified" or "Approved" are not required, and do not indicate that the unit is in fact a qualified arrester."