WF10X 18mm Biological Microscope Wide angle Eyepiece Optical Lenses with Scale Features: Made of high-quality optics and metal, it is durable and practical. The magnification is WF10X, the image is bright and clear, and the effect is clearer. When using this product, the eyes are not easily fatigued, which can effectively protect eyesight. The national standard installation size is 23.2 mm, which is suitable for most biological microscopes on the market. Built-in reticle with scales for easy adjustment of the angle, calibration of the position of the measurement object, easy to observe. The wide-angle eyepiece has a large viewing angle and a wide field of view, which not only improves the softness of the vision, but also makes the image clearer and brighter. Specifications: Condition: Material: Optical glass, metal Magnification: WF10X Field of view: 18 mm Quantity: 1Pcs Installation size (diameter): approx. 23.2mm / 0.9in Package list:  1 * Eyepiece