Adjust the Focusing Ring for Precise Calibration: When changing the 1.25 inch eyepiece of the telescope; refocusing is not required; enabling rapid switching; maintain sharp focus for planetary observation and astrophotography
All-Aluminum metal Construction: It is treated with black anodic oxidation; featuring excellent wear resistance and a long service life; precisely processed to ensure compatibility with a variety of telescope eyepieces
Easily Increase Magnification: With parfocal ring equipped telescope eyepieces you can change magnifications quickly and easily; this set of three Astromania parfocal rings lets you make more efficient observing
Wider 58 Degree Field of View: Comfortable eye relief averaging 16 mm across the series and focal lengths is between 2.5 mm to 25 mm; giving maximum detail and definition across the entire 58 degree field of view
Multi-coated Lense Design: Each eyepiece has 5 lens elements in 3 groups; with retaining high transmittance and contrast ratio with least lateral cchromatic aberration and scattering phenomenon; having a wide view