1、Performance: Inner diameter is 25mm/0.98in, and to prevent the microscope's objective lens from falling off and causing damage. 2、Excellent Features: Professional and practical design with exquisite appearance, compact structure, easy to carry and use. 3、Wide Application: Usually wide used in laboratories, schools, teachers, sample observation, eyepiece protection, etc. 4、Essential Parts: Microscope pillar bar adapter is an essential microscope accessory, reliable and dependable, easy to install. 5、Reliable Material: This ring is made of durable ABS and metal material, sturdy and stable, and can be used for a long time. 1 x Microscope Pillar Bar Adapter Item Type: Microscope Pillar Bar AdapterMaterial: ABS and metalInner Diameter: Approx: 25mm/ 0.98in