For racers who don't need the lowest guide nut possible, for body clearance, these .150" tall, dual set screw, collars, don't require threading, and install almost effortlessly, with no wobble, using a standard tire wrench.
CR074 - aluminum - zip-loc bag of 3 - $10.50 retail ($3.50 each)
CR075 - brass - zip-loc bag of 3 - $11.85 retail ($3.95 each)
No set screws included.
Use your own favorite, leftover, lucky set screws.
Will be available at Eagle and ERI with a full discount.
If you have a local raceway, please encourage them to stock them so you can purchase from them.
I will send a free sample, of either material, to anyone who has placed a $25+ order, from me.

Perfect fit on an unthreaded Red Fox post, of either material. Will obviously also fit on smaller diameter posts.

For no wobble installation, take JK lane sticker backing paper, "notch" it out with a paper punch, and push down hard, alternating, tightening each set screw.
On a full height post, using another collar to push down with, works well.

Free rotating, and no perceivable wobble.
I have also adjusted the collar, to be able to get the blade of an 8" screwdriver in between the tongue and collar, and every effort to pry it off, resulted, with a ton effort, snapping the guide at the base.
The 2 set screws, "keying" themselves, into a non-metallic surface, have never showed any inkling, to allowing the collar to slip.