Pony clamps are economic and efficient tools for on set work. Their sizes correlate with the width of their opening. 1 is a 1 inch, a 2 a 2 inch, and a 3 is a 3 inch. Pony clamps are a great general tool for everything from clamping fabrics to a grid to keeping boards together for construction. Protective covers on some models help prevent indenting and scratching the items they’re gripping.