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
Wide Range of Compatibility: Standard 1.25 inch female thread can be connected with 1.25 inch focuser of telescope or any other 1.25 inch telescope accessories, threaded for standard 1.25 inch astronomy filters and barlow lens
Exquisite Detailed Design: Fold-down rubber eyeguard offers a soft cushioned surface; the matte blackened lens edges effectively prevent stray light; coming with sturdy plastic dust caps-protect the eyepiece from dust and moisture