The ornamental design for a staplerefill, as shown and described.
FIG. 1 is a perspective view of a staple refill showing my new design;
FIG. 2 is a perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The broken line showing of the staple refill is included for the purpose of illustrating portions of the staple refill and forms no part of the claimed design.