A surgical instrument comprises a handle (1416) and a transducer (1414) configured to produce vibrations. The transducer comprises at least one piezoelectric element, a gripping portion (1422) and a mounting portion configured to be operably coupled with an end effector (1446). Said transducer (1414) is configured to produce a standing wave of vibrations in said transducer and the end effector, wherein said standing wave comprises a node and an anti-node. The handle (1416) is configured to be placed in a first configuration in which it is disengaged from said gripping portion (1422) and a second configuration in which it is engaged with said gripping portion (1422), and the handle (1416) is further configured to hold said gripping portion (1422) in position when said handle is in said second configuration and when the end effector (1446) is being mounted to said mounting portion of said transducer.
