1、Application: This adjustable focal length mount is suitable for objective lens sizes of 50mm, attachment pillar sizes of 22mm, and center distance of 135mm. 2、Stable Structure: Made of high strength alloy material, black appearance, the bracket has stable structure, ensure stable and clear image effect. 3、High Performance: Easy to attach, convenient to use, the adjustable focus stand can be precisely adjusted to ensure bright and clear image. 4、Application: Perfect microscope accessories, exquisite workmanship, can be widely used in microscope, with good durability and stability. 5、Fine Workmanship: Professional manufactured, exquisite workmanship with unique design, ensure stable performance and high reliability. 1 x Adjustable Focus Stand Item Type: Adjustable Focus StandMaterial: Metal alloyApplicable Objectives Lens: Approx. 50mm/ 1.97inApplicable Connection Pillar: Approx. 22mm/ 0.87inCenter Distance: Approx. 135mm/ 5.31in