12 dioptres (4.0X) optical quality glass lens mounted on a swing arm. Compatible with Daylight magnifiers iQ (U25100) Quadra (U25120) Omega 7 (U25130) and iQ Magnifier (U25100). The arm easily slides on the rim of the magnifier. No tools required. Mounted on a swing arm 12 dioptres (4.0X) Easily slides on the rim of the magnifier no tools required Lens Ø: 4 cm (1.5″) Lens material: Optical quality glass Magnification: 12 dioptres (4.0X) Colour: light grey Weight: 0.11 kg (0.24 lb)