The Putting Arc MS-3DThe Putting Arc MS 3D Based on the original Putting Arc MSIII, the new MS 3D allows you to use the toe or the heel of the putter for training. It includes an adjustable mirror for feedback on the position of the head and shoulders. The product is an all weather, lightweight, more versatile version of the deluxe wooden model. Weighing only 2. 2 pounds, the Putting Arc MS 3D is 33 in length enough for a full stroke for most standard length putts.