4" Galvanized Transition (3-1/4" x 10" Round)

This transition piece enabled me to vent an off-brand microwave oven (for which I had none of the accessory parts, such an exhaust tail piece) directly out the back, through the wall, and to the outside air. I did modify the transition piece by removing the extra flange material that was riveted to the 10x4 opening, and once I had that off, it was fairly easy to conform the piece's opening to fit the space I cut out for it. The 4" circular end of the transition perfectly jutted outside about an inch, which will be perfect for adding a hood with flapper. I could not find this transition piece in the store, so it was a great relief to find it here at SupplyHouse.com.