A surgical instrument comprising: (a) a body assembly comprising: i. a casing, ii. an outer sheath extending distally from the casing; iii. an inner tubular actuation member or rod disposed within the outer sheath, wherein either: a) the inner tubular actuation member or rod or b) the outer sheath, is operable to actuate longitudinally relative to the other of: a) the inner tubular actuation member or rod or b) the outer sheath; and iv. a latch member coupled to the casing, wherein the latch member comprises an electrical connector; and (b) a transducer and blade assembly comprising: i. a transducer wherein the latch member is pivotable relative to the casing to selectively axially restrain the transducer within the casing, wherein the transducer comprises a notch having a ring connector disposed therein, and ii. a blade assembly acoustically coupled to and extending distally from the transducer, wherein the blade assembly is operable to sever tissue; and (c) a detachable end effector selectively coupleable to a distal end of the outer sheath and a distal portion of the inner tubular actuation member or rod, and operable to clamp tissue against a distal end of the blade assembly. (a) a body assembly comprising: i. a casing, ii. an outer sheath extending distally from the casing; iii. an inner tubular actuation member or rod disposed within the outer sheath, wherein either: a) the inner tubular actuation member or rod or b) the outer sheath, is operable to actuate longitudinally relative to the other of: a) the inner tubular actuation member or rod or b) the outer sheath; and iv. a latch member coupled to the casing, wherein the latch member comprises an electrical connector; and i. a casing, ii. an outer sheath extending distally from the casing; iii. an inner tubular actuation member or rod disposed within the outer sheath, wherein either: a) the inner tubular actuation member or rod or b) the outer sheath, is operable to actuate longitudinally relative to the other of: a) the inner tubular actuation member or rod or b) the outer sheath; and iv. a latch member coupled to the casing, wherein the latch member comprises an electrical connector; and (b) a transducer and blade assembly comprising: i. a transducer wherein the latch member is pivotable relative to the casing to selectively axially restrain the transducer within the casing, wherein the transducer comprises a notch having a ring connector disposed therein, and ii. a blade assembly acoustically coupled to and extending distally from the transducer, wherein the blade assembly is operable to sever tissue; and i. a transducer wherein the latch member is pivotable relative to the casing to selectively axially restrain the transducer within the casing, wherein the transducer comprises a notch having a ring connector disposed therein, and ii. a blade assembly acoustically coupled to and extending distally from the transducer, wherein the blade assembly is operable to sever tissue; and (c) a detachable end effector selectively coupleable to a distal end of the outer sheath and a distal portion of the inner tubular actuation member or rod, and operable to clamp tissue against a distal end of the blade assembly.