Fulton 4 Inch To 2-1/2 Inch Reducer, Shop Vacuum & Dust Collector Accessories, Hose to Hose Dust Collector Adapter Fitting For Port Connections on Larger Machinery

As described works great

The correctly sized hoses fit well on each end of this. These fittings are available all over, so I chose this based on price. But Fulton is a very good woodworking tool brand; I have a table saw miter gauge from them that is extremely accurate and useful. For these reducing fittings, I prefer the cone-shaped taper to those that have a flat divider punctured by the smaller exit tube. A tapered fitting doesn't disturb the air flow so much.

There needs to be an option to buy a 4 inch inside diameter or a 4 inch outside diameter depending on your tool port size.

Definite upgrade over my cobbled up duct tape adaptation!Perfect way to do it right!

I bought a new saw that didn't have a 4 inch dust collector port. This was perfect. It accepts a 2 1/2inch hose inserted the same way you would insert a brush or a blade fitting on a shop vac. It's a male 4 inch fitting with a female 2 1/2 inch fitting. Well made, works well.

Purchased this to adapt to my CNC Router dust boot. Works great.

My Leigh dovetail jig has a dust collector fitting of 2 3/8 diameter (2.42 OD) and the Fulton has a smaller opening of 2 3/8 (2.46 OD). The Fulton was to go to a 4" duct to a vacuum collector. So the adapter I will make from PVC or vinyl will be 2 3/8 to 2 3/8 OD.Maybe duct tape?

So many BIG tools and devices use 4" but my small shop mostly needs 2 1/2" or smaller. This transition works well because it is tapered. I use it to transition from the big gulp under my table saw to the 2 1/2" hose further down the line in my system. It seems to easily keep suction even with the reduction in size.Some dust collection parts are interchangeable with plumbing, but most sizes don't match up, so when you need a specific part you have to pay the freight and get a true dust collection fitting, like this.