DONEGAN P937 3-7X MAGNIFIER Pocket magnifier provides magnification and viewing for a variety of applications such as jewelry-making, watch-making, needlework, artwork, fly-tying, electronic inspection, book-reading, print inspection, and stamp-collecting Available in multiple dioptric strengths that provide a specific magnification power (X), depending on the distance from the object (focal length) A dioptric number and a magnification number are not the same thing. Diopter strength represents a specific magnification power (X). For example, a 5-diopter provides 2.5X magnification (at a distance of 8”) Double, round lens system that slides into case for storage, and fits in a trouser pocket or a purse Durable, dustproof, plastic, round case that slides open for use as a handle, and clicks closed to protect the magnifier when not is use