Coolest hazardous materials sign!

I found this sign on a truck from Tennessee which is for sale, here in Benin. The sign's leaves turn over like pages in a book, so the one sign actually shows six plus warning signs which can be changed to show whatever hazardous load the truck is carrying. Maybe these signs are common in the US and UK now, but I've never seen one before and think it is the coolest thing since sliced bread. Modelled by Anna. Olly