A medical device comprising: an elongate tubular member; an inner member lumen longitudinally extending through the tubular member; an elongate inner member longitudinally extending and movably disposed in the inner member lumen; and a collet coupled to a distal end of the tubular member, the collet comprising: a collet body; and a central lumen longitudinally extending through the collet body and configured to receive the elongate inner member, wherein the collet body comprises an inner surface defined by the central lumen, and wherein the inner surface of the collet body exerts an inward force on the elongate inner member when the elongate inner member is disposed within the central lumen of the collet to create a frictional force that provides resistance to longitudinal movement of the inner member at the distal end, wherein the collet is press fit to a distal end of the tubular member and in that a cross-sectional area of the central lumen is dimensioned relative to a diameter of the elongate inner member such that when the collet is press fit to the distal end and the elongate inner member is disposed within the central lumen, the frictional force that is created is within a range that is greater than a maximum external force to cause longitudinal movement of the inner member relative to the tubular member during operation of the medical device, and less than a longitudinal force exerted on the inner member by a control mechanism of the medical device that is operatively coupled to the inner member, and characterised in that the collet body is dimensioned relative to the tubular member so that the press fit between the collet and the distal end of the tubular member causes a reduction in the cross-sectional area of the central lumen for creation of the frictional force in the range. an elongate tubular member; an inner member lumen longitudinally extending through the tubular member; an elongate inner member longitudinally extending and movably disposed in the inner member lumen; and a collet coupled to a distal end of the tubular member, the collet comprising: a collet body; and a central lumen longitudinally extending through the collet body and configured to receive the elongate inner member, wherein the collet body comprises an inner surface defined by the central lumen, and a collet body; and a central lumen longitudinally extending through the collet body and configured to receive the elongate inner member, wherein the collet body comprises an inner surface defined by the central lumen, wherein the inner surface of the collet body exerts an inward force on the elongate inner member when the elongate inner member is disposed within the central lumen of the collet to create a frictional force that provides resistance to longitudinal movement of the inner member at the distal end, wherein the collet is press fit to a distal end of the tubular member and in that a cross-sectional area of the central lumen is dimensioned relative to a diameter of the elongate inner member such that when the collet is press fit to the distal end and the elongate inner member is disposed within the central lumen, the frictional force that is created is within a range that is greater than a maximum external force to cause longitudinal movement of the inner member relative to the tubular member during operation of the medical device, and less than a longitudinal force exerted on the inner member by a control mechanism of the medical device that is operatively coupled to the inner member, and characterised in that the collet body is dimensioned relative to the tubular member so that the press fit between the collet and the distal end of the tubular member causes a reduction in the cross-sectional area of the central lumen for creation of the frictional force in the range.