The Double Wall Ductwork Series has been certified by ITS. 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.

Models DW-2R and DW-3R are ETL listed under file number 1000082319SAT-006 EEV and comply with UL1978, UL2221, CAN/ULC-S115, CAN/ULC-S662, and ASTM E814 Standards.

Model DW-3Z is ETL Listed under file number 1000082319SAT-006 EEV and complies with UL1978, UL2221 and CAN/ULC-S144 Standards.