All bells have the same diameter at the thread as well as at the far end, are however in each case about 5 mm higher than the previous one. Thus, the L-bell (seen from the screw) flares somewhat faster than the M bell, and the XL even more strongly. M is the standard bell for the Brendan, L for the Americus and the XL belonged in former times to the Concorde model (which at present is no longer available). The different bells can be combined partially with the different tapers, then the Brendan can be played also well with the L-bell or Brendan as well as Americus with the XL bell. L gives somewhat more volume to the sound. XL produces a sound characteristic similar to the Conn 8D.