Features:1. Aluminum Alloy shell is precision machined, stable and durable for long time use.2. This is a 10X achromatic objective lens for biological microscope.3. It can eliminate unwanted reflections and increase contrast.4. Offers high quality observation without additional chromatic aberration, make image more clear.5. The Length of the objective lens is 31.3mm, easy to use.Specification:Item Type: Achromatic Objectives LensMaterial: Aluminum Alloy + Optical LensColor: As Pictures ShowMagnification: 10XTube Length: 160mm / 6.3inchConjugate Distance: 185 Cover-glass Thickness: 0.17mm Objective Lens Length: 31.3mmMounting Size: 20mm（Standard RMS Thread)Item Size: 5 * 5 * 5cm / 2.0 * 2.0 * 2.0inchPackage Weight: Approx. 55gPackage List:1 * Achromatic Objectives Lens