The Double Wall Ductwork Series has been certified by UL. This certification mark indicates that the product has been tested to and has met the minimum requirements of a widely recognized (consensus) U.S. Product safety standard, that the manufacturing site has been audited, and that the applicant has agreed to a program of periodic factory follow-up inspections to verify continued performance.
Model DW-2R Type HT is UL Listed under file number MH60233 and complies with UL103, UL103HT, CAN/ULC-S629-M87, and ULC/ORD-C959-1993.