Excellent design. Built bit fiddly.

The luminaires feature a very beautiful design and good functionality when you since installed correctly. Completely unnecessary, indeed disturbing, is the tilt of the used LED lamp, since LEDs do not emit any case in a particular direction and no reflector is present. I have installed in my house entrance outside. Moisture and sometimes splashing can not harm them if they rest on a smooth flat surface, because they are a relatively thick silicone sealing ring against protected.

The construction is quite delicate and requires a degree of craftsmanship, care and a bit of tact during installation.
The electrical connection does not cause problems. Anyone who has ever connect a lamp, so that is easy done.
However: The retaining springs of the lamp have the thickness of pins. The tabs on the metal base to which they are attached, can be bent upon insertion into the intended ceiling opening, the spring may slip off the nose. This can happen if the lamp is not quite straight bzw.mittig held during insertion, but canted something may well happen, since the slide the retaining springs are under tension. That must be so, for the lamp also fits well and tight. I jumped off a spring in a case with the insertion of light and disappeared in the ceiling cavity. Hand can reach through the 68 mm hole in any case. Attach a small magnet with electrical tape to a slightly thicker wire, insert the wire through the opening and search the vicinity of the well with the magnet until the spring (audible) is detected by the magnet: The solution. Opens guaranteed.
If tilted, the actual LED bulb in the ceiling during insertion of the lamp, this is not corrected from outside, because the LED sits behind the outwardly visible glass pane. So for the correction you have to pull out the lamp again.

Overall a very visually beautiful, functional part, when it is installed only once because clean.