Hate to revive an old thread but wanted to clarify something based on my own experience. I just received two of the aforementioned DCI 3-hole borden connectors, part number 0121, and the three holes are NOT three different sizes. There is a large hole and two smaller holes, however the two smaller holes are indeed the same size. Close but not exactly correct. I think the only difference between 121T and 0121 is that the former comes with the nut and connector and the latter is just the connector. If anyone knows from where a correct Borden connector can be obtained, if it's even possible at all, I'd love to know.