Another type of wheel cover, the "static wheel fairing", was introduced by BBS for Ferrari at the British Grand Prix to act as a brake cooling aid for front wheels whilst remaining stationary the wheel itself with one part being cut out at a 27° angle to enable hot air to escape and thus became adopted by every team. The wheel covers were banned from use in F1 from 2010 after incidents where they broke loose in races. To get around the ban, Ferrari used a detachable integral aero device made from the same magnesium material as the wheel itself, which consisted of double concentric rings of different diameters. As parts of cars now have to be homologated, its rivals were unable to copy this device. Its use became eliminated when the FIA revised the regulations for 2011 to prohibit wheel materials in certain exclusion zones.