This new innovation of an old ships pilot favorite, from Weems & Plath, has quickly become our best selling parallel ruler. After you've tried it, you'll wonder why they never thought of it years ago. The unique 3-arm construction allows a much greater parallel ‘walk’ without the diagonal creep associated with traditional designs. Although only 12” in length, it can provided a reach equivalent to an 18” parallel ruler. Milled with beveled edges, 0.19 inch thickness, with aluminum arms and handles.