A hand-held functional valve sizer device having a longitudinal axis and includes a slider housing portion enclosing multiple sliders, a handle portion connected to the slider housing portion via a malleable rod. The handle portion includes a handle, a guide casing, a ring sizer selecting mechanism, and, a trigger for pushing down at least one selected ring sizer for functional assessment of the valve, and, multiple ring sizers protruding from the distal end of the slider housing portion. Particularly, every ring sizer is operably coupled to each slider, and an operator selects at least one ring sizer by operating the ring sizer selecting mechanism for an assessment of the functional aspect of the valve. FIG. 1
