20-25, 30-35, 40-45 & 50-55 mm diameter spheres.
Four different examples of stands for crysrtal spheres or balls.
Body 25 will take 20 to 25mm dia balls, 35 will take 30 to 35mm diameters and so on.
Alternativly each example could be scaled up or down to suit the required diameter.
I made these from ASA and smoothed them using acetone, but you can use any filament to make them.