2-----3 inch adjustable elbows and a mailbox. Oh, OK, I used a couple of screw clamps as well. Not a single thing was done to the MES except take out the chip loader and the chip tray. The 3 inch elbow fits nice and snug in the chip loader hole. No need for any caulking or sealing of any kind. The only somewhat hard part was cutting the hole in the back of the mailbox. Just gave it a run today and could run my top vent a quarter open with no loss of smoke draw from the mailbox. This was my first run of my new AMNPS, which is why I did the mod. Worked just great. One channel was filled with Sugar Maple and it gave me about 2 hours of smoke. Couldn`t be happier.