Hyperion Fine-Tuning Ring 14mm for Baader Hyperion Eyepieces and M48 Extension to 2" Outer Diameter. Extension ring with dual M48 x 0.75 filter threads and a length of 14mm. The adapter is made of aluminum and is black anodized. It increases the magnification of the Hyperion eyepieces by approximately 23%. Screw the extension ring between the lower element of the Hyperions and the eyepiece body, and the focal length of the eyepiece is reduced by about 23%. The magnification increases by the same amount. Thread: M48x0.75 on both sides (male/female). Length: 14mm. Length of M48 internal thread: 3mm.