Zirconia stabilised with Yttria has similar properties to those of Zirconia stabilised with Magnesia, although it is harder and tougher. It also has a finer grain structure. The non-woven fabrics are felts fabricated by mechanically locking fibres, and firing at a high temperature. The fabrics are flexible and chemically unreactive, being especially stable to hot caustic. Applications include thermal insulation, filtration and catalysis. The properties above are those of the sheet form.