Rigid Duct Straight Connector with Damper and Wall Plate. Comes with integral back draft shutter (damper or non-return valve). Available in 4, 5 or 6 Diameters. 4 Rigid Duct Straight Connector with Damper & Wall Plate Domus EasiPipe 100 is suitable Bathroom, Toilet and Utility room applications Free Area 7,850mm2 5 Rigid Duct Straight Connector with Damper & Wall Plate Domus EasiPipe 125 is suitable for Bathroom, Toilet, Utility room, Kitchen and Whole House Applications. Free Area 12,266mm2 6 Rigid Duct Straight Connector with Damper & Wall Plate Domus EasiPipe 150 is suitable for Kitchen, Commercial and Whole House Applications Free area - 17,263mm2