calimaero TVE Round Stainless Steel Adjustable Vent Valve 4" Inch 4054503000308

calimaero® TVE 4 inch - Round Stainless Steel Adjustable Vent Valve 100 mm Fits Only with Metal Ducts

WeCooper 100mm - 4 inch Connector with Backdraught Shutter, Non-Return Damper Flap to Connect Duct Pipe or Flexible Hose Pipe

neverest® ESD 100mm in-line Duct Sound Absorbing Tool Sound Insulation Silencer for Round Ventilation Pipes