Details: The KFM Magnifier, is recognized as the world's number one magnification system. A 5" diameter, 5-diopter (2.25X) optical-quality lens is mounted in a die-cast aluminum housing which is non-corrosive and durable. The inside is finished in white to optimize and evenly distribute light. A 30" patented internal spring K-arm offers an infinite number of adjustable positions and an adjustable neck moves the Magnifier, head vertically and horizontally to provide total flexibility. Once adjusted, perfect balance is maintained by tempered steel springs. An electronic ballast system with RFI filter eliminates noise and produces 15% greater light output. Instant-on switch: Just a touch of a switch ignites the fluorescent tube instantly and creates a "flicker-free" light that eliminates the stroboscopic effect on machinery such as a lathe or drill press. Weighted base. UL/cUL listed. Color: Light grey.