The ornamental design for a sprinklerbase, as shown and described.
FIG. 1 is a perspective view of a sprinkler base with a turret oriented vertically;
FIG. 2 is a front view of the sprinkler base of FIG. 1 with the turret oriented vertically;
FIG. 3 is a right side view of the sprinkler base of FIG. 1 with the turret oriented vertically; and,
FIG. 4 is a top view of the sprinkler base of FIG. 1 with the turret oriented vertically.
The left side view of the sprinkler base is the same as the right side view and the rear view of the sprinkler base is the same as the front view when the turret is oriented vertically.