Comfortable to hold and easy to use, perfect for your larger rulers, templates and triangles. Features a large contoured grip handle and a large round suction cup with lock and release lever. A unique feature of this Gripper is its two-color installation indicator, which shows you at a glance if the suction cup is securely afffixed to the ruler. Will work with smooth surface rulers that are at least 4-1/8" wide. A lightweight, heavy duty tool.