Description Product Description The 180S-37 features a #37 bell with a medium-fast taper to produce a sound that has a brilliant sound with a warm quality that allows this instrument to work well in multiple musical settings-from jazz to concert or solo playing. The #25 leadpipe allows for slight resistance that is effective in centering tone production. These features combined with a .459-inch medium-large bore allow the player to produce a well-rounded sound while not over-extending the endurance level of the player. The Monel valve material allows the pistons to be machined to a consistent diameter throughout the entire length of the valve to produce a more efficient "seal" between the piston and the interior wall of the valve casing. The result is less air leakage that could cause performance problems.