Galvanized Ductboard Straight Spin-in's with Damper #2000 Hercules Spin-In`s for fiberglass ductboard. Choose from either straight or conical. This product is durable and easy to use. SKU 2004 Product Details | Specifications | Check Inventory Please select 4" DUCT-BD SPIN-IN-DPR 50/CTN 5" DUCT-BD SPIN-IN-DPR 48/CTN 6" DUCT-BD SPIN-IN-DPR 32/CTN 7" DUCT-BD SPIN-IN-DPR 18/CTN 8" DUCT-BD SPIN-IN-DPR 10/CTN 9" DUCT-BD SPIN-IN-DPR 12/CTN 10" DUCT-BD SPIN-IN-DPR 6/CTN 12" DUCT-BD SPIN-IN-DPR 4/CTN 14" DUCT-BD SPIN-IN-DPR 2/CTN 16" DUCT-BD SPIN-IN-DPR 1/CTN 18" DUCT-BD SPIN-IN-DPR 1/CTN 20" DUCT-BD SPIN-IN-DPR 1/CTN Log in to view price