Yes that's the one - GRZ101. they specify 1mm error, I think that includes pointing error and the other centring errors you may get when mounting it on a point.
Coincidentally I just had an email from SECO 1 hour ago about this new product you may be interested in.
You will still have pointing errors unless you can view it from the same angles each time, but it does give you a couple of choices without having to move it.
Thanks for the report I will digest it at leisure...
ps you would need to be aware of the limitations of this prism.
I can search and lock on it up to about 100m away with Trimble S6.
The Leica "powersearch" does not work with this prism.
That email from seco is what got me to thinking...
I wonder if that 1.5 mm "pointing accuracy" is just that-meaning it can determine the horizontal angle to that accuracy. If you read Kivioja's report you will see the reason for the extra path length, and that it is minimized for offsets in the -30 mm range. So I suspect that there is still some effect from misalignment, although it is definitely different than the 360° prisms that I have. They are actually a number of small prisms set around a circle. So, sometimes you may be looking directly at one and other times you might be shooting in between.
Little by little I see optical tooling gizmos and field surveying gizmos converging. Sort of like the scanner sphere/retro reflector posting above ...
I actually built a working prototype for my own use years ago. I was able to cobble together RC parts and house it into a 4inch diameter PVC fitting with some machined aluminum parts top and bottom. Worked very well although the range was around 1000 ft and I thought that was not long enough to be a commercial success. Kept it around for years but did not use it in the field.