Astro-Tech 114mm Tube Rings

These split and hinged optical tube mounting rings are made of solid aluminum, anodized black for long life. They are felt-lined and have a large hand-tighten knob to lock them on your optical tube. A heavy nylon washer prevents the knob from marring the anodized finish. The rings have a 114mm internal diameter to fit refractors with a 114mm OD tube, such as the Astro-Tech AT90EDT apo triplet, Takahashi TSA-102, FS-102, and original FSQ-106, William Optics FL-105 and ZenithStar 110, plus any other scope with a 114mm OD tube. The rings weigh 14.4 oz. each.

There are five mounting holes on bottom of the rings for mounting on most equatorial mount dovetail plates. The center three holes are 6mm metric threaded, while the outer two are 1/4"-20 thread. One 6mm hole is centered in the flat mounting boss in the bottom of each ring. It is flanked by a pair of 6mm holes on 60mm centers, and a second wider pair of 1/4"-20 holes on 80mm centers. An identical set of five holes on the top of each ring allow installing a second dovetail plate to carry accessories.

Two 16mm long x 6mm hex head metric bolts are supplied with each ring for mounting the ring on a dovetail plate or equatorial mount using the center hole or two flanking holes.