This is a beautiful light fitting, but it is not a sealed unit and is only suitable for very large bathrooms.
I had never heard of zoning for lights, but my electrician explained it all to me. There are 3 zones and it all depends on how far away from the source of steam it will be positioned.
My bathroom is of average size and needs a zone 1 light, which will be a sealed unit otherwise steam can enter the unit and cause a fire!
There was no mention of zones in the description, all it said was that it was a bathroom light.