The Spot On Dot Magnifying Lens Set allows you to see exactly where you’ve lined up your fabric on your ruler by giving you magnified visibility at the point that matters most. For precision-perfect accuracy, the Spot On Dot is the perfect tool! Simply place the 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 those precise cuts. The Spot On Dot will stay in place until you remove it. Store the lenses in the included case after each use. You can reactivate the grip on the Spot On Dot by simply washing with mild soap and water.