Not universal at all (1/5 stars)
This review is supposed to be have a 1 star rating, but the review submit form won't accept it. This company is very dishonest. This is not universal at all. It requires a cup with a rim measuring very close to 73 mm inside diameter and 76 mm outside diameter. It seems like it would stretch to fit a larger range, but instead the silicone slowly slips off (after about 3 minutes). The collar has an inside rim, so it will not work with an undersized cup. Most jars will not work because the threads cause the rim to be much larger than 1.5 mm thickness. I was unable to find anything in my collection of cups and jars that this will work on. Also, if you want to use a cup with a handle, the top of the handle must be at least 11 mm below the rim of the cup. This measurement requires the collar to be rotated so the narrowest outside portion of the lip is aligned with the handle. At the time this review was written, this part of the collar was not shown in the product pictures. Alternatively, the entirety of the collar could be inserted into the cup. This requires the inside diameter of the cup to be at least (and not much more than) 82 mm. In this case you must rely on gravity to hold the collar in place, and the number of holes available for brushes may be reduced. At the time this review was written, this is the way the collar is shown being used in the product pictures.
Get the whole kit
The collar can stretch to various cup sizes, but then it just slips off. Womp womp. I'd say skip the collar thing and get the kit with the cup that's made for it. It's great. The collar on its own is not.
I LOVE IT!
I'm truly enjoying my Paint Puck and the universal collar! They're PERFECT for me!