Speedi-Products EX-HJBW 04 4-Inch Diameter Hood J-Block. White Speedi-Exhaust Products are made in the USA The J-Block design has a reversible trim ring to accomodate brick, siding and stucco applications Weighted damper prevents wind noise and animal entry. Seal joints with approved duct mastic sealants and tapes Consult your local building codes for approved installation practices