It is compatible with 8" duct
+ Product Details Size – 16" x 16" is the size for the duct opening measurement only
+ Product Description Introducing the 6" Butterfly Damper – Your Solution for Controlled Airflow
+ Product Details Size – 36"w X 18"h is the size for the duct opening measurement only
L/H@0 FT: - 250
HVAC Premium Left Cut Aviation Snips - Metal, Tin Cutting Shears Return Grille It is compatible with 8"Professional Aviation Snips Perfect for Tile, Bolt, Tin, Metal, Roofing, Siding, Wire, Sheet Metal, Branch, Duct, DIY, Home Improvement, etc Cutting HEAVY DUTY CUTTERS These Left Cut Aviation Snips have a SawTooth Design, Edge Serration that can cut Stainless Steel below 0. 6mm or Iron Plate below 1. 2mm Cut Iron Like Paper SHARP SNIPS Head, forged with 50 CR V Chrome Vanadium Steel for superior strength Cutting Edges and Optimal Durability EASY