An adapter for selectively interconnecting a surgical end effector that is configured to perform a function and a handle assembly that is configured to actuate the end effector, the end effector including at least one axially translatable drive member, and the handle assembly including at least one rotatable drive shaft, the adapter comprising: an adapter housing configured and adapted for connection with the handle assembly and to be in operative communication with each rotatable drive shaft of the handle assembly; an outer tube having a proximal end and a distal end, wherein the distal end of the outer tube is configured and adapted for connection with the end effector and for operative communication with each axially translatable drive member of the end effector; an inner housing (262', 264') having proximal and distal ends defining a longitudinal axis wherein the inner housing is rotatably supported in the adapter housing; and at least one drive converter assembly for interconnecting a respective one rotatable drive shaft of the handle assembly and one axially translatable drive member of the end effector, wherein the at least one drive converter assembly includes a first end that is connectable to a rotatable drive shaft of the handle assembly and a second end that is connectable to the axially translatable drive member of the end effector, wherein the at least one drive converter assembly converts and transmits a rotation of the rotatable drive shaft of the handle assembly to an axial translation of the axially translatable drive member of the end effector; characterised in that; the adapter housing has an inner wall surface defining a cavity, wherein a flange projects radially inward from the inner wall surface on the distal end of the adapter housing; the outer tube tapers distally from a larger diameter to a smaller diameter, the outer tube rotatably and translatably supported by the flange of the adapter housing, the inner housing (262', 264') having an inner wall surface defining a cavity and an outer surface, wherein an annular groove is defined in the proximal end of the inner wall surface, wherein a diameter of the outer surface of the inner housing is less than a diameter of the inner wall surface of the adapter housing, and wherein the at least one drive converter assembly is configured to be rotatably and translatably supported in the annular groove in the inner housing. an adapter housing configured and adapted for connection with the handle assembly and to be in operative communication with each rotatable drive shaft of the handle assembly; an outer tube having a proximal end and a distal end, wherein the distal end of the outer tube is configured and adapted for connection with the end effector and for operative communication with each axially translatable drive member of the end effector; an inner housing (262', 264') having proximal and distal ends defining a longitudinal axis wherein the inner housing is rotatably supported in the adapter housing; and at least one drive converter assembly for interconnecting a respective one rotatable drive shaft of the handle assembly and one axially translatable drive member of the end effector, wherein the at least one drive converter assembly includes a first end that is connectable to a rotatable drive shaft of the handle assembly and a second end that is connectable to the axially translatable drive member of the end effector, wherein the at least one drive converter assembly converts and transmits a rotation of the rotatable drive shaft of the handle assembly to an axial translation of the axially translatable drive member of the end effector; characterised in that; the adapter housing has an inner wall surface defining a cavity, wherein a flange projects radially inward from the inner wall surface on the distal end of the adapter housing; the outer tube tapers distally from a larger diameter to a smaller diameter, the outer tube rotatably and translatably supported by the flange of the adapter housing, the inner housing (262', 264') having an inner wall surface defining a cavity and an outer surface, wherein an annular groove is defined in the proximal end of the inner wall surface, wherein a diameter of the outer surface of the inner housing is less than a diameter of the inner wall surface of the adapter housing, and wherein the at least one drive converter assembly is configured to be rotatably and translatably supported in the annular groove in the inner housing.