Thanks for the description and drawing of the bracket. Really authentic drawing.

No problem, I'd imagine none of us here would really want to pay the 100 or so dollars that the OEM Advance bracket costs for some stupid reason. I wonder if lack of demand for these is why the brackets are so expensive, same goes for the MSRP of the ballasts themselves for that matter.

And btw, for the slot/hole that the ballast nipple goes through, the official size is a 1-3/8" slot but I didn't have a end mill in that size and I wasn't about to go buy one so I used a 1-1/2" end mill to make that slot. It works but the nipple fits a bit sloppier than if the slot was 1-3/8"

Updated the listing links as some has since sold.

The 400w version should be used with this GE Form 400 I found on eBay:

See here:

https://www.ebay.com/itm/223987484713