Today, the Geen 321 Batt Ear (R) arrived. The Blue Prism on the (L) I thought was a 321 but it has a number of differences There is really only one similarity between the two pieces which makes me think I'm missing something???

Umbrella diameter: 6.25" for (both) is the only similarity. Umbrella underside - flat: (R). Umbrella underside - rounded: (L). Inner Skirt - outer diameter: 2-9/16" (L), & 2-7/8" (R). Cable Groove opening: 3/4" (L), & 1-1/8" (R). Umbrella undersides and ears are different .

Thanks to Bill M. for a little feedback. Both are CD 321's and the left is a known variant in the hobby.