Alvin - Swing-Arm Magnifier Lamp - 60 Watt - Black - The Alvin Swing Arm Magnifier Lamp has spring suspension system for adjusting to any position. Arm height adjusts to 36 inches maximum. This Magnifier Lamp has a 4 inch diameter optically fine-ground 3-diopter glass lens with 1.75x magnification. Metal clamp. Uses a 60w bulb (not included). Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.