A delivery device (10; 110) for a collapsible prosthetic heart valve, the delivery device comprising: an operating handle (20; 120), including: a frame (30; 130) defining a movement space (34; 134) therein; a carriage assembly (40; 140) moveable in a longitudinal direction within the movement space; and a coupler (60; 160) having a locked condition in which the coupler is connected to the frame in a fixed position, and an unlocked condition in which the coupler is movable in the longitudinal direction within the movement space, the coupler being operatively connected to the carriage assembly for movement therewith; and a catheter assembly (16; 116), including: a first shaft (26; 118) around which a compartment (23; 123) is defined, the first shaft being operatively connected to the frame, the compartment being adapted to receive the valve in an assembled condition; and a distal sheath (24; 124) operatively connected to the carriage assembly, the distal sheath being moveable between a closed condition adapted to maintain the valve in the assembled condition and an open condition adapted to fully deploy the valve, wherein movement of the carriage assembly in the longitudinal direction in the movement space moves the distal sheath between the closed condition and the open condition, characterized in that the carriage assembly is movable in the longitudinal direction relative to the coupler, and that the coupler is selectively lockable to the frame in any of a plurality of fixed positions in the longitudinal direction. an operating handle (20; 120), including: a frame (30; 130) defining a movement space (34; 134) therein; a carriage assembly (40; 140) moveable in a longitudinal direction within the movement space; and a coupler (60; 160) having a locked condition in which the coupler is connected to the frame in a fixed position, and an unlocked condition in which the coupler is movable in the longitudinal direction within the movement space, the coupler being operatively connected to the carriage assembly for movement therewith; and a frame (30; 130) defining a movement space (34; 134) therein; a carriage assembly (40; 140) moveable in a longitudinal direction within the movement space; and a coupler (60; 160) having a locked condition in which the coupler is connected to the frame in a fixed position, and an unlocked condition in which the coupler is movable in the longitudinal direction within the movement space, the coupler being operatively connected to the carriage assembly for movement therewith; and a catheter assembly (16; 116), including: a first shaft (26; 118) around which a compartment (23; 123) is defined, the first shaft being operatively connected to the frame, the compartment being adapted to receive the valve in an assembled condition; and a distal sheath (24; 124) operatively connected to the carriage assembly, the distal sheath being moveable between a closed condition adapted to maintain the valve in the assembled condition and an open condition adapted to fully deploy the valve, a first shaft (26; 118) around which a compartment (23; 123) is defined, the first shaft being operatively connected to the frame, the compartment being adapted to receive the valve in an assembled condition; and a distal sheath (24; 124) operatively connected to the carriage assembly, the distal sheath being moveable between a closed condition adapted to maintain the valve in the assembled condition and an open condition adapted to fully deploy the valve, wherein movement of the carriage assembly in the longitudinal direction in the movement space moves the distal sheath between the closed condition and the open condition, characterized in that the carriage assembly is movable in the longitudinal direction relative to the coupler, and that the coupler is selectively lockable to the frame in any of a plurality of fixed positions in the longitudinal direction.