A system for delivering a medical device within vasculature, comprising: a sheath assembly; a medical device retained in the sheath assembly; and a handle assembly including a shuttle assembly connected to the sheath assembly, the handle assembly further including a trigger handle connected to a trigger sliding component adapted to move longitudinally within the handle assembly, the trigger sliding component mating with a pulley retainer and the pulley retainer in turn engaging an idler retainer when the trigger handle is located in its most forward position, such that the pulley retainer is moveable with the trigger sliding component, the handle assembly further including a belt attached at one end to the shuttle assembly and at another end to a thumbwheel assembly, the belt (i) being arranged vertically at its connection to the shuttle assembly and extending proximally from the shuttle assembly to a proximal spool, (ii) extending distally from the proximal spool and being horizontal along a portion of its length when extending distally from the proximal spool, (iii) being routed about a pair of idlers (82,86) of the idler retainer and a trigger pulley of the pulley retainer, and (iv) extending proximally from the pair of idlers (82, 86) to be connected to the thumbwheel assembly, wherein actuation of either the trigger handle or the thumbwheel assembly accomplishes longitudinal movement of the shuttle assembly within the handle assembly. a sheath assembly; a medical device retained in the sheath assembly; and a handle assembly including a shuttle assembly connected to the sheath assembly, the handle assembly further including a trigger handle connected to a trigger sliding component adapted to move longitudinally within the handle assembly, the trigger sliding component mating with a pulley retainer and the pulley retainer in turn engaging an idler retainer when the trigger handle is located in its most forward position, such that the pulley retainer is moveable with the trigger sliding component, the handle assembly further including a belt attached at one end to the shuttle assembly and at another end to a thumbwheel assembly, the belt (i) being arranged vertically at its connection to the shuttle assembly and extending proximally from the shuttle assembly to a proximal spool, (ii) extending distally from the proximal spool and being horizontal along a portion of its length when extending distally from the proximal spool, (iii) being routed about a pair of idlers (82,86) of the idler retainer and a trigger pulley of the pulley retainer, and (iv) extending proximally from the pair of idlers (82, 86) to be connected to the thumbwheel assembly, (i) being arranged vertically at its connection to the shuttle assembly and extending proximally from the shuttle assembly to a proximal spool, (ii) extending distally from the proximal spool and being horizontal along a portion of its length when extending distally from the proximal spool, (iii) being routed about a pair of idlers (82,86) of the idler retainer and a trigger pulley of the pulley retainer, and (iv) extending proximally from the pair of idlers (82, 86) to be connected to the thumbwheel assembly,