This small rubber abrasive stone is handy for erasing rust from edges, or gently "softening" sharp tip and tail edges where they lift up out of the snow.
It can also be used for on-the-slope edge touch-ups and polishing.
Since it"s softer than a hard stone, it"s more forgiving if you"re using it without a bevel guide.
It measures 3 x 1 x 5/8" so it easily fits in parka pockets to carry with you.