Mid-height heels are from 2½ to 3½ inches (8.5 cm). They are an intermediate between standard heels and "stiletto heels", which are from 4 to 10 inches. The extreme heels are made of steel, and very narrow at the base: 0.4 inches or less. These have been widely criticised for the health risks regular wear would bring. They have also been criticised by feminists. If the soles of the shoes are also raised, then they are a quite different kind of shoe: the "platform shoe".