An apparatus for imparting a tensile force to deflect a distal portion of a catheter while maintaining its exterior dimensions may include a handle grip including a cross-section of generally predetermined exterior dimensions, and a longitudinal axis. A flexible elongate member may include proximal and distal end portions, with the proximal end portion being coupled to the handle grip. An adjustment knob may include a cross-section of generally predetermined exterior dimensions, and is rotatably coupled to the handle grip around the longitudinal axis. An elongate deflection member may be operably coupled to the adjustment knob and to the distal end portion of the elongate member. Rotation of the adjustment knob may impart a tensile force to the deflection member thereby causing the distal end portion of the elongate member to deflect from a prior configuration while maintaining the generally predetermined exterior dimensions of the handle grip and the adjustment knob.