Tutu steel - thread covered 9.5mm (3/8 inch) black
Tutu steel is thread covered hoop steel. This one is 9.5 mm wide and black.
To use hoop connectors with this product (scroll down), you may need to wrap the cut ends in tape, pry up the openings of the connectors with a slot screw driver and then slide the connectors onto the cut ends; otherwise the thread gets pushed back and does not slide into the connector.
hoop steel thread covered 9.5 mm black
I've been told that the standard 15" tutu requires a bit more than 2 meters of hoop wire, if you order 3 meters you should be safe.