The Bourdon bell, Great Tom, pitched G, has a weight of 11,000 pounds and a diameter of 79.5 inches. The smallest bell, pitched C, weighs 20 pounds, with a diameter of 8 inches. The total bell weight is 61,312 pounds making it one of the heaviest instruments in the world. In 1992, a five and a half octave "North American Standard" practice keyboard was installed. This keyboard is now located at the Carillon Offices and is throughout available to the resident Carillonist and guest Carillonists.