I've connected this to a 4" thin walled, white, drain pipe ducting that runs 10' up the wall, 25' across/above the ceiling (in the attic) then has a port hanging down in the middle of my shop with a 4" and a 2 1/2" Y connector (ITEM# T20559; 4" x 4" x 2-1/2" Y-Fitting) and hoses. It came with the 30 Gallon Dust Collection 2 Stage Separator. I've also installed blast gate ports on the hoses and back at the separator to give me options. There is no problem running both hoses open as I have several pieces that I run both a 2 1/2" and the 4" vacuum hoses at the same time. The Separator is pretty much a "must have" as it saves on filling up the plastic bag on the dust collector and makes it much easier to empty the wood shavings....only the fine dust gets on into the plastic bag. Others have commented that the separator lacks a great deal when it comes to attaching hoses and sealing to a trash can. I have attached pictures of how I adapted connectors to the separator. I also put a soft sponge rubber gasket under the separator where it contacts the lip of the trash can and hold the lid down with a bungee cord extended from one trash can handle to the other over the top of the separator (don't really need bungee as the suction pulls the lid down tight). The hose connections are a 4" blast gate on one and a 4" hose to 4" hose connector on the other. I simply put a rubber tube gasket material around where the blast gate/hose to hose connector contact the separator holes, applied a strip of rubber strapping to the hose to hose connector in front of the gasket to give it something to push the gasket against the separator. The rubber strip wasn't needed on the blast gate side as it has a large flange that functions to push the gasket against the separator. A 1/4" self tapping screw (I pre-drilled just in case to avoid cracking/splits) was used to secure the blast gate to the face of the separator opening and from the top on the hose to hose connector side. You could just as easily use a blast gate for both...like all dust collection system descriptions, you have to figure out what pieces you need to connect the pieces you want to use...and we all end up with extra "pieces" after we are done! Hopefully the pictures help explain the verbiage above. 1) connectors in place before adding gaskets; 2) gasket on blast gate; 3) side view of hose to hose piece installed with gasket and rubber "bumper" strip; 4) front view of same; 5) finished , front view; 6) finished, top view.