The ornamental design for a counterbalance, as shown and described.
FIG. 1 is a front perspective view of the counterbalance of the present invention;
FIG. 2 is a back perspective view of the counterbalance shown in FIG. 1;
FIG. 3 is a front elevational view of the counterbalance shown in FIG. 1;
FIG. 4 is a rear elevational view of the counterbalance shown in FIG. 1;
FIG. 5 is a left side elevational view of the counterbalance shown in FIG. 1;
FIG. 6 is a right side elevational view of the counterbalance shown in FIG. 1;
FIG. 7 is a top plan view of the counterbalance shown in FIG. 1; and,
FIG. 8 is a bottom plan view of the counterbalance shown in FIG. 1.
The broken line showings of fasteners, e.g., screws, rivets, nuts, bolts, etc., depicted in the figures are for the purpose of illustrating various fasteners, and form no part of the claimed design. The broken line showing of a spring assembly depicted in the figures is for the purpose of illustrating a linear actuator, and forms no part of the claimed design.