Doc, you have the correct part number, but it's been discontinued. I know when you google it you will see a number of places showing that it's still available, but it's not. I'm not saying that you won't find one at a dealer, but chances are slim. I will see if I can locate any, but I'm pretty sure that I got the last of the .25 and .50 rings awhile back. I'll be doing more sizes as requests come in. Thanks, Ron