It can adjust the eyepiece position to help you get a clearer image. Applications: Supports all types of telescopes, including reflectors and refractors, for observing star clusters, the Moon, planets, and other celestial bodies. Made of all-metal construction; no glue required, formaldehyde-free, environmentally friendly, and does not require adhesive installation. The metal ring thread is directly screwed on without glue, ensuring a secure fit that will never come off or debond over time. No black glued pressing ring. Please measure the outer diameter of your telescope objective lens to select the correct size. Do not choose based solely on the lens diameter. For example: 127SLT has an outer diameter of 146mm suitable for 160 solar film; 8SE has an outer diameter of 235mm suitable for 250 solar film. Type: 140mm / 80mm / 100mm / 120mm / 160mm Color: As shown Material: Metal Package Contents: 1 x Composite membrane filter Note: The package includes only the items listed above. Other products are not included. Light reflection and differences in display screens may cause slight variations in color between the image and the actual item. Measurement error allowance is +/- 1-3 cm.