The Prima Luce Lab PLUS 115mm guide rings are the easiest solution to install a guide telescope in parallel with your main telescope. The 115mm rings will fit guide scopes with an outer diameter of between 53mm - 110mm.
These rings belong to the PLUS system (Prima Luce Universal System) that includes a large variety of telescope rings, bars, guide rings and dovetail clamps. The rings have a system of drilled and threaded holes that maximize the compatibility between parts, allowing several mechanical combinations and assembly solutions.
Each component of the PLUS system is carved from aluminium blocks that are CNC machined. Then, the aluminium is sandblasted to achieve a very smooth surface finish and is anodized (hard anodizing) to increase the hardness of the material and to protect it from oxidation.
The 115mm guide rings PLUS can be:
- connected directly to all the PLUS compatible components using 2 screws or to support rings of other brands.
- screwed on the PLUS dovetail bars (Vixen or Losmandy).
If you have mechanical accessories from other brands, you can still use all the elements of the PLUS system through the central hole of the ring.
While there is not much one can say about single-use objects like mounting rings, there were a couple of points which struck me when I received and examined them.
Firstly, they are quite sturdy, and could be used for fairly weighty equipment, but light in weight.
Secondly, they come with a flattened part of the ring so that they could be mounted directly onto, say, a telescope mounting bar. If this isn't to your liking, and you would prefer a "nice" round ring assembly, Prima Luce Lab have thoughtfully provided fill-in sections with screws.
Thirdly, the 'scope mounting screws are each tipped with a nylon pad that doesn't dent or scratch (unless you are over enthusiastic in tightening them). They seem to hold objects quite well without undue tightening.
Overall, I am impressed with the quality, design and workmanship of these rings. I am using mine to hold a long image train firmly in place while my 'scope tracks the sky. The rings clamp onto my imaging camera and the arrangement is rock solid, without any sign of damage to the camera's casing. I am well pleased with my purchase!