Mask Focusing Mask for Telescopes, Acrylic Pinpoint Telescope Focusing Mask for Tube Outer Diameter from 60mm to 90mm, with 3 Stable Metal Posts Wide Range of Applications: Works with all types of telescopes, mirrors, refractors, all you need to do is measure your telescope tube size and choose the appropriate mask size. Masks Function: The mask takes the guesswork out of focusing and even overcomes vision conditions to give your telescope the best focus quickly and easily. 3 Metal Posts: The mask grips the telescope tube gently and firmly with three metal posts. These metal posts come with scratch resistant silicone covers to protect your telescope surface. This prevents slippage while keeping the mask perfectly centered. Post Installation and Lightweight Design: Thanks to this 3 post mount, the mask remains centered while fitting a wider range of telescopes. The focus mask for telescopes is lightweight so you won't upset the balance of the scope. Color: Gold Size: Inner diameter is about 60mm, outer diameter is about 90mm Delivery Quantity: 1 Piece Warm prompt: 1.As different measuring methods,it will occur 1-3 cm deviation about the items,please ensure that it is okay for you before ordering. 2. Because of different monitors and lamplight, the picture may not reflect the actual color of the item, really thank you for your kind understanding 3. Only the above package contents, excluding other products. Products from JINYI's store