While I am aware of the different heights of different kegs, what I was not aware of is different circumferences. Most of the kegs I have are about 8.5 inches in diameter. I found 2 that are about 8 inches. That is going to help me get two into my fermenting fridge and start to ferment and dry hop in my kegs. I am going to measure them out and see how much, if any, headspace I have for a 5 gallon batch. I am pretty stoked as I can now store a keg at the ready in the fermenting fridge and have it ready when my serving keg goes dry. I will still have to transfer it into my serving keg as it needs to be a shorter height than the ones I have, but at least I can do my fermenting and storing in controlled temps and get away from bottling and plastic buckets. We will see, the collar is still in the works as well.