I am off learning and teaching at Marc Adams School of Wood Working, expect shipping delays for next 2 weeks..
Life is sometimes like "Goldilocks and the Three bears". When I interact with other makers half the time someone wants a deeper net groove and the rest of the time they want it shallower. When I designed the cutter I tried to put it about 1/2 way between three bearings. One is too swallow, one is too deep and one is just right. The smaller bearings will work on any of the arbors I supplied in the past. The bigger bearings need the Whiteside arbor that I am supplying with a bearing arbor about 1 3/16 inches long.
One more point, it is really hard to know the quality of the bearings that I get as a small supplier, so I can make no claims about quality. The bearings in the past were marked with the county of origin but it is no longer a uniform standard. I try to get ABEC 5 bearings but I can't really be sure. I have used these bearings in my shop for years, but one batch to the next can be a problem.
The pricing is for a set of 6 bearings, a pair of bearings 19mm, 22mm and 24 mm in diameter. (The 22 mm bearings are the ones that are supplied with my custom router bit.) (Packaging will vary.)