Len diameter: 25mm. there is LED light, is helpful for you. Material: Plastic This extremely powerful Loupe is 4 times more powerful than the average (10x) loupe. Magnification: 40x Lens Diameter: 25mm Illumination: LED light Light powered by 3 LR927 batteries (included) Size: 5(L) x 3(W) x 2.5(H)cm approx Package Includes:2x 40x 25mm Eyes Optical Glass Loupe Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Great product for the watch making industry, specially for inspecting those tiny objects. Good for coins, stamps and antiques etc.. Foldable and tiny, great to have one in your pocket all the time High Quality Eye Magnifying Glass. Color : Black