1. Using coaxial fastening, the inner ring is made of PETF material, which can be quickly and synchronously locked without harming the eyepiece and other accessories 2. Allows the use of M42 eyepieces with telescopes that normally require a 1.25-inch eyepiece 3. Material: metal 4. Net weight: about 71.8g 5. Size: about 5.5 x 3.15cm
