Finally got my P68 last week and I'm going to start the installation Saturday morning. I thought I had everything together, but when I went to slide the stove into place this evening I decided to go ahead and hook the flex pipe from the Simpson Wall Thimble with Air Intake kit that I bought up to the air intake on the back of the stove. Well, after trying unsuccessfully I decided to read the info about the kit and find out that the kit comes with 2" flex pipe and the Harman needs 2 3/8" flex pipe. Does anyone have any suggestions as to where I can get the 2 3/8" that I need?? Thanks in advance.