These TMB 114mm 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 (4.5”) internal diameter specifically to fit the TMB-92 refractor, but will also work with any other refractor having a 114mm OD tube. The rings weigh 25 oz. each.

There are five 1/4”-20 thread mounting holes on bottom of the rings for mounting on most equatorial mount dovetail plates. One hole is centered in the flat mounting boss in the bottom of each ring. It is flanked by a pair of holes on 60mm centers, and a second wider pair of 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.

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 142mm (5.6”) internal diameter specifically to fit the TMB-130 refractor, but will also work with any other refractor having a 142mm OD tube. The rings weigh 25 oz. each.

There are five 1/4”-20 thread mounting holes on bottom of the rings for mounting on most equatorial mount dovetail plates. One hole is centered in the flat mounting boss in the bottom of each ring. It is flanked by a pair of holes on 60mm centers, and a second wider pair of 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.

This short focal length 5mm TMB Planetary II eyepiece is from TMB Optical, the company founded by noted apochromatic refractor designer Thomas M. Back to produce state-of-the-art premium optics. It is designed to give you exceptional high power views with short to medium focal length refractors and reflectors – even under so-so seeing conditions.

This short focal length 6mm TMB Planetary II eyepiece is from TMB Optical, the company founded by noted apochromatic refractor designer Thomas M. Back to produce state-of-the-art premium optics.

The 6mm TMB Planetary II has been optimized to show maximum contrast, detail, and definition when viewing bright objects such as the Moon and planets, both on and off axis. It has very high light transmission and contrast, plus minimal lateral color and light scatter. These combine to provide exceptional high power observing with long focal length refractors, reflectors, and catadioptric scopes under average or better seeing conditions. That you can get its truly premium performance at such a reasonable price is little short of amazing.

This short focal length 7mm TMB Planetary II eyepiece is from TMB Optical, the company founded by noted apochromatic refractor designer Thomas M. Back to produce state-of-the-art premium optics.

The 7mm TMB Planetary II has been optimized to show maximum contrast, detail, and definition when viewing bright objects such as the Moon and planets, both on and off axis. It has very high light transmission and contrast, plus minimal lateral color and light scatter. These combine to provide exceptional high power observing with long focal length refractors, reflectors, and catadioptric scopes under average or better seeing conditions. That you can get its truly premium performance at such a reasonable price is little short of amazing.

The 8mm TMB Planetary II has been optimized to show maximum contrast, detail, and definition with a wide variety of telescope types and focal ratios when viewing bright objects such as the Moon and planets. It has very high light transmission and contrast, plus minimal lateral color and light scatter. These combine to provide exceptional high power observing, both on and off axis, with long focal length refractors, reflectors, and catadioptric scopes under average or better seeing conditions. That you can get its truly premium performance at such a reasonable price is little short of amazing.

This TMB refractor optical tube is exceptional in optics and mechanics. The high standard optics this telescope makes this telescope one of TMB's best! This instruments excels at solar imaging because the high quality ED glass prevents aberration which results in very clear and sharp views. TMB has also added anti-reflective coatings that result in fantastic image contrast.