Supply Giant 6I49x4 Flexible Coupling, 4 inch, Black

DO NOT buy this if it's for a dust collection system. It's for schedule 40 plumbing pipe and it's bigger than advertised to accommodate the wall thickness. I get it now...but I still think it's highly lame that they didn't make that clear on theirMy 4" coupling measures 4.25". I will now have to cut the coupling, remove a section, and seal off with a piece of thin EPDM and contact cement. Annoying.

I purchased these because they were significantly cheaper than the PowerTec, Woodcraft and Rockler rubber couplers. Unfortunately, they are too wide for a standard 4" dust hose and 4" PVC pipe. They will work if you cinch down the straps but the couplers will then mushroom out. If you don't mind that the couplers look like fat rubber mushrooms they'll work, otherwise I would order the PowerTec rubber dust couplers instead.

07/31/2021:Update: I'm currently rebuilding my dust collection system (removing old duct tape, replacing some hose with 4" pvc pipe and replacing connections with these couplers). I am thoroughly impressed with these couplers. With a little effort you can work these over the larger elbow/splitter end. You can use a flat head screw driver but a drill with a 8mm socket will be way faster for tightening. I have had to add additional ceiling strapping to hold up the additional pipe and because the rubber coupling are a heavier than tape. Be showing picture soon.07/19/2021: Update: I change my rating because even though there is a lot of space between the couplings and a 4" pipe the rubber is flexible enough to really clamp down and hold air tight. I use all four of them and I am presently surprised.Ordered another set of 4.Disregard my previous rating.+++++++++++++++++++++++++++++++++++++++++++This coupler is way bigger than 4"It is closer to 4.5"The pictures do show the inside diameter as 4.5"...my 'beef' is then why call them 4" couplers.My bad...an I'll eat this one, but it won't happen again!

Very heavy rubber coupling that will conform to old pipe that's no longer round, has high quality stainless clamps. This will work until I replace all the 4" to my septic.

Used these to connect central duets collection pies in woodsho. Heavy duty and cheaper than I could purchase at local hardware store. Great value and arrived expediently.