Just to nail it home, the smaller ones fit 1/2 inch pillar taps. The larger ones are for Bath mixers, way too big. I would expect these are identical to the millenia handwheels, but with new and improved caps?
The smaller ones look to be the intermediate version that were made somewhere between the correct ones and the oversized version. I've had those and they're close in size to the correct ones, but don't come apart at all except for the cap. The flat gaps between the cubes are a little wider as well.