This bundle includes tools to make shanks travel vertically (as opposed to just parallel to each other) and hammers vertical at strike, two important preparations for best power, fastest repetition, least wear, and optimized voicing. The Squaring Platform provides the horizontal, height adjustable surface from which the Shank Traveler says yes or no to each shank's travel and from which the Hammer Square Articulated guides the vertical squaring of hammers while they are supported at strike. And the Depth/Angle Gauge sets up the Squaring Platform to the same height at all four corners.