Quantum Precision 80 LED Rolling Base Professional Magnifier Lamp - Extra-Large, Wheeled Base Utility Trays Extra-large 7.5-inch x 6.25-inch rectangular glass lens, optical-quality 5-diopter magnification Professional Lab Quality 80 High Performance Heavy-duty clamp system holds firm to desk or tabletop up-to 2.5-inches thick without damaging furniture Heavy duty non-tipping base that rolls easily Power switch located on lamp head for easy access, 72-inch power cord; UL listed