Material: PS or Acrylic material, mainly PS.
Size: different sizes for choosing.
When it comes to the size don't fit well: we would suggest the slightly larger coin box with a red/white/black ring. This solution would works well for fixing your coin in the capsule or a coin slab.
The rings could be customized into different diameters, and you could display different size of ring in one capsules/coin slab, only needs to change the ring inside to save the cost.
Package: we could do custom package according to your demands.