Product Description: Aluminum Alloy shell is precision machined, stable and durable for long time use. This is a 100X objective lens for biological microscope. It can eliminate unwanted reflections and increase contrast. Offers high quality observation without additional chromatic aberration, make image more clear. The Length of the objective lens is 36.5mm, easy to use. Material: Aluminum Alloy + Optical Lens Color: As Pictures Show Magnification: 100X NA: 1.25 Conjugate Distance: 185 Cover-glass Thickness: 0.17mm Objective Lens Length: 36.5mm Mounting Size: 20.2mmStandard RMS Thread) Package Weight: 46g Package Include: 1 x Microscope Objectives Lens Note: Please allow 0-2mm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you If you really care about these details, pls DO NOT order. 185 Conjugate Distance The 185 conjugate distance is the distance between the object plane and the image plane of the objective lens in the microscope system. Optical lens It can eliminate unwanted reflections and increase contrast, offering high quality observation without additional chromatic aberration, make image more clear. Aluminum alloy case The outer casing material of the objective lens is made of aluminum alloy and is durable. The aluminum alloy is corrosion resistant and will not rust when exposed to water or chemicals. It can be used in the laboratory. The surface is finely polished and the touch is smooth and comfortable. Standard RMS Thread Standard RMS thread, 20.2mm mounting size, please confirm the size of your microscope thread before purchase.