Review on Double Oxygen Sensor Fitting Kit With Notched Bungs And Plugs, M18X1.5 Thread Size, By Ledaut - Ideal For Mounting O2 Sensors by Jacob Brasic

I have no issue with the quality of thee bung, but I wish the description would specify the pipe diameter used for the notch. The notch on the bung fits perfectly on my 1" socket, which is about 1.33" diameter. I bought these for my custom exhaust made with 2.5" pipe, but with a notch for such a small diameter, I had about 1/8" gap to fill at the high side of the notch. Alternatively, I could do some grinding to make them fit better, but I decided to return these and find some with a more appropriately sized notch.