Clamp-On BaseThe Lighted Attach-A-Mag Desk Magnifier is a fully adjustable, flexible arm magnifier. Lens Size: 4.3 Inches.Weight: 5.6 Oz.This Lighted Desk Magnifier is very handy for hobbies, reading and assembly. Hands free Lighted Desk Magnifier Lamp: Use for hobbies and crafts, inspection, assembly, bench magnifier.