OK, the stuff I got was:
Supplier: SEFAR Pty Ltd
Description: SST304 1220MM 3.3mm AP 0.91mm Wire
Cost: $81.00 per linear meter
So basically it is stainless steel mesh that is made with 0.91mm thick wire, and has a 3.3mm sized hole.
You can look at their Stainless Steel Mesh options here: SEFAR - Metal Mesh
and look at the "Market Grade Woven Wire" pdf file.
I bought 1.1m which did 6 hives so worked out about $15 per 10 frame hive
I haven't been back to the hives to check again but they've been on the hives for over a year and I've been very happy with them so far.
I bought some spare mesh which is going into a bee vac, and I will also be able to use it as a mesh top on a hive if I want to move them on a really hot day. Also I kept all my offcuts and some were big enough to use to close entrances when I move the hives.