This DuraVent Direct Vent pipe is 4 in. inner x 6 5/8 in. outer and the length is 9 in.,  a few paint defects on this Pipe, but in good working condition.

DuraVent Direct Vent Pro Chimney Pipe is engineered and approved to vent just about any gas and propane stove in the industry. It's advised to check the owner's manual of your appliance to be sure DuraVent Direct Vent Pro is approved. The outer wall of the Direct Vent Pro pipe brings in the combustion air and the inner wall is dedicated to the exhaust from the appliance. Non-Returnable. One Available.