FIG. 1 is a perspective view of a sprinkler base showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a diagram showing the operation status of the first sprinkler mounted to the base thereof; and,

FIG. 9 is a diagram showing the operation status of the second sprinkler mounted to the base thereof.

The broken line showing of the sprinklers mounted in the claimed design in FIGS. 8 and 9 are included for the purpose of illustrating and forms no part of the claimed design.