The ornamental design for the hand-held instrument, as shown and described.
FIG. 1 is a perspective view of a hand-held instrument of my design with a movable support depicted in the extended position, the indicia on the panel and buttons being no part of the claimed design;
FIG. 2 is a front view thereof, the indicia on the panel and buttons being no part of the claimed design;
FIG. 3 is a rear view thereof, with a movable support depicted in the retracted position;
FIG. 4 is a right side view thereof, with a movable support depicted in the extended position;
FIG. 5 is a left side view thereof, with a movable support depicted in the extended position;
FIG. 6 is a bottom plan view thereof, with a movable support depicted in the extended position; and,
FIG. 7 is a top plan view thereof, with a movable support depicted in the extended position.