Donegan Optical LP 2 Replacement Lens for Opti-Visor, 1.5x Magnification, 2 Diopters, 20-Inch Focal Length Replacement lens plate for OptiVISOR magnifier which provides hands-free magnification and viewing for a variety of applications such as jewelry-making, watch-making, needlework, artwork, 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) Optical-grade, acrylic lens plate ground and polished into a prismatic lens for quality, clarity, and durability High-strength, durable plastic lens plate offers simple fit in OptiVISOR magnifier visor