They arrived. Local insured mail is troublesome, and the post office mentioned that for security reason, there is no delivery service. I've finally fetched it during lunch hour. The nearby post office is not "secure" enough and so I'll have to take a bus for 10 minutes traveling, and then walk back office afterward for around 20 minutes. Troublesome especially during this rainy season.
I first unpacked the EOS T-ring, it's made in Japan as indicated from the box, it's well made and quite heavy as you pick it up. This ring consists of two parts, the outer part contains the interface to the EOS mount. I took a camera mount cap to office to see if it's a good fit. Yes, it's a perfect fit. And this ring is connected to a T-thread ring via several small set screws. With this configuration, the inner part can be common to any camera mount, and the added benefit is that, you can rotate the camera with respect to the inner ring, but then I don't think it's very useful?
Next, I unpack the 1.25" T-adapter, actually, it's just a T-thread to 1.25 nosepiece with filter thread. I plan to use it with my BF10, and also maybe my Ranger, or any 1.25" only telescopes.
Then I unpack the 2" EOS adapter. It was sold for nearly double from another vendor, so I went for this one instead. I want to use it with my Borg, and maybe my Sky90, as well as my C5. What makes it different from the above combination is that, it didn't go through the T-thread, i.e. one side of it connects to the EOS mount, and the other side is a 2" nosepiece. That should reduce vignetting, since T-thread is smaller than 2". This adapter is also threaded for 2" filter. When I unpacked it, to my surprise, it actually consists of the same T-ring as above! But there's one major different, and it's also why it's so different is that: I said the above T-ring has two parts, now, the outermost part which connects to the EOS mount is the same, but then the inner part does not produce T-thread but instead it's a very nice machined 2" nosepiece!
So, I ended up to have two identical parts, but anyway, it's still nice for it brings convenience, you don't have to remove it and re-attach it everytime.
Finally, that a 8.5" dovetail plate. It's Vixen GP compatible, it's made from solid aluminium and it has a couple of holes and slots pre-dilled to allow different mounting rings, etc. No screws were included in the package. Two of the holes are threaded, and I guess they're 1/4". There are three other holes which should accommodate 3/8" screws and the screw heads can be recessed inside. There are also two other slots like the above 3/8" holes and this adds flexibility. I will use this one to mount my Borg, my Canon as well as my KM DC there side by side.