Trademark Tools Swing Arm Incandescent Magnifying Lamp With Clamp, Black: * Powerful optically ground 3-diopter magnifying glass * Versatile flexible arm extends up to 36" * Fully adjustable to almost any position with steel springs and tension-control knobs * Multi-use clamp mounts on tables or other flat surfaces up to 2.25" thick * Gives excellent lighting and allows hands-free use * Requires a 60-watt maximum bulb (not included) * Lens measures 3.75" in diameter