Suncourt 4-Inch Centrax Inline Centrifugal Fan — Quiet Duct Fan for Exhaust, Ventilation, or Inline Boosting, Safety Certified, Simple Installation, 10-Foot Power Cord (TF104-CRD)

Suncourt Centrax TF104-CRD In-Line Centrifugal Duct Booster Fan (4 inch) with Button Control, Improved Air Flow for Better Indoor Heating and Cooling

EesTeck 4" (Diameter) Adjustable 304 Stainless Steel Duct Clamps Hose Clamp Pipe Clamp Air Ducting Clamp worm drive hose clamps (4Pcs, 91mm-114mm)

AC Infinity Flexible 4-Inch Aluminum Ducting, Heavy-Duty Four-Layer Protection, 25-Feet Long for Heating Cooling Ventilation and Exhaust