We claim the ornamental design for a mid-filament spacer, as shown and described.
FIG. 1 is a perspective view of a mid-filament spacer according to a fifth embodiment.
FIG. 2 is a front side view of the mid-filament spacer depicted in FIG. 1, with the back side view being identical to the front side view.
FIG. 3 is a left side view of the mid-filament spacer depicted in FIG. 1, with the right side view being identical to the left side view.
FIG. 4 is a top view of the mid-filament spacer depicted in FIG. 1.
FIG. 5 is a bottom view of the mid-filament spacer depicted in FIG. 1, with dashed lines indicating environmental portions that form no part of the claimed design; and,
FIG. 6 is a bottom view of a sixth, alternative embodiment of the mid-filament spacer, which has top, left, right, front, back and perspective view are identical to those depicted with respect to the embodiment shown in FIGS. 4.
The broken lines immediately adjacent the shaded areas on the bottom views of the embodiments described above represent the bounds of the claimed design and are for illustrative purposes only; the broken lines form no part of the claimed design.