Abstract: A multi-modulus probe design and assembly are disclosed. In one implementation, the system may include a stiffening element extending along at least a portion of a length of a lumen containing electrical wires for electrodes used in an Electrohydraulic Lithotripsy (EHL) probe. The stiffening element may be contained within the lumen of the probe or may extend along an outside of the probe. The stiffening element may be an assembly of wires of different modulus of elasticity that are joined together with a non-conductive sheath such that a greater stiffness is provided at a proximal end, and a lesser stiffness is provided at a distal end near a tip of the probe.