The mark consists of a three-dimensional configuration of a ladder-stabilizing apparatus consisting of eight views of the configuration. The apparatus has a generally inverted triangular shape being larger at the top and tapering to a narrow tip at the bottom, clamping jaws which hook out from the upper portion and back towards the tapered portion, a bar and oblong opening therefor at the top, a handle with trigger opposite the clamping jaws, rubber feet on the clamping surfaces and below the clamp, and screw heads and bolts with openings thereto distributed over the generally inverted triangular shape. The handle and trigger and clamping jaws are yellow, the rubber feet are black, and the generally inverted triangular shape is orange with black lateral faces. In the center between the upper and lower halves of the black lateral faces there is a triangular design in orange. The locking bar, screw heads, and nuts are silver. All aspects shown are claimed as features of the mark.