A catheter, comprising: a handle ; an elongated body ; a basket-shaped electrode assembly mounted at a distal end of the elongated body, the basket-shaped electrode assembly comprising a plurality of spines ; a first inner lumen disposed within the elongated body; a second inner lumen disposed adjacent to the first inner lumen; and a seal , the seal having a first opening corresponding to the first inner lumen and a second opening corresponding to the second inner lumen, the seal fixedly attached to a distal end of the elongated body; wherein the elongated body further comprises a spine collar , the spine collar comprises a plurality of outer lumens and wherein the first inner lumen and second inner lumen are disposed within the spine collar; characterized in that : the second inner lumen houses a pull-wire , the pull-wire disposed longitudinally within the second inner lumen; the second opening of the seal is of a dimension to provide a friction fit seal around an outer surface of the pull-wire; the pull-wire is afforded longitudinal movement relative to the catheter body so that it can move the distal ends of the spines proximally or distally relative to the catheter body to radially expand and contract, respectively, the basket-shaped electrode assembly; the handle comprises an actuator coupled to the pull-wire, wherein the actuator is configured to adjust a longitudinal position of the pull-wire relative to the catheter body. a handle ; an elongated body ; a basket-shaped electrode assembly mounted at a distal end of the elongated body, the basket-shaped electrode assembly comprising a plurality of spines ; a first inner lumen disposed within the elongated body; a second inner lumen disposed adjacent to the first inner lumen; and a seal , the seal having a first opening corresponding to the first inner lumen and a second opening corresponding to the second inner lumen, the seal fixedly attached to a distal end of the elongated body; wherein the elongated body further comprises a spine collar , the spine collar comprises a plurality of outer lumens and wherein the first inner lumen and second inner lumen are disposed within the spine collar; characterized in that : the second inner lumen houses a pull-wire , the pull-wire disposed longitudinally within the second inner lumen; the second opening of the seal is of a dimension to provide a friction fit seal around an outer surface of the pull-wire; the pull-wire is afforded longitudinal movement relative to the catheter body so that it can move the distal ends of the spines proximally or distally relative to the catheter body to radially expand and contract, respectively, the basket-shaped electrode assembly; the handle comprises an actuator coupled to the pull-wire, wherein the actuator is configured to adjust a longitudinal position of the pull-wire relative to the catheter body. the second inner lumen houses a pull-wire , the pull-wire disposed longitudinally within the second inner lumen; the second opening of the seal is of a dimension to provide a friction fit seal around an outer surface of the pull-wire; the pull-wire is afforded longitudinal movement relative to the catheter body so that it can move the distal ends of the spines proximally or distally relative to the catheter body to radially expand and contract, respectively, the basket-shaped electrode assembly; the handle comprises an actuator coupled to the pull-wire, wherein the actuator is configured to adjust a longitudinal position of the pull-wire relative to the catheter body. <EOS>