The BC Series - These British cornet backbores are shorter than the standard cornet backbores. They were specifically designed for use with the BC tops, resulting in an overall length of 2.25". These are very popular with brass band enthusiasts. The Star means they are designed to allow each of the STANDARD models to be more free-blowing without the necessity of reaming to a larger bore size. This may help to avoid losing focus sometimes caused by playing too large of a backbore. Since these models were made available, the medium large sizes (7* to 10*) have been very well received by orchestral cornet players.