Vent Systems 5" inch to 4" inch Duct Reducer Adapter Connector Fitting Pipe Increaser Reducer Cone for HVAC Ventilation Systems, ABS Plastic PVC pipe 125 to 100 mm - Amazon.com
5pcs 12mm PVC Straight Elbow Tee Connector Four Way Joint 90 120 135 Degree 1/4" PVC Pipe Adapter DIY Wardrobe Tent Fittings (Color : 135 Degree, Size : 12mm) : Amazon.ca: Tools & Home Improvement