The small dot is 1 inch in diameter. The large dot is 2 inches in diameter. At the center, magnification is 3x.
Place Spot on Dot adhesive side down onto your favorite ruler at the spot you want to magnify. The reusable adhesive ring will prevent the Spot on Dot from shifting while you make precise cuts. The Spot on Dot stays in place until you remove it. Store in it's case after use. You can reactivate the grip on the Spot On Dot by simply washing with mild soap and water.