Have this Spos (20, KG, EC) in my partitions (10 cm thick) installed and am very satisfied. As a flush-mounted box I used a standard can (approximately) and the spots mounted therein. In my case I had made the wallbox the white plastic ring almost completely removed so that the spot fits. Fixed I have the whole then with Knauf Putty. Then grind and white paint -> ready.
The spot covers the wallbox from very accurate and you must be careful that the light does not escape laterally. So I recommend it to fix the spots with putty.
The illumination on the stairs is great. The spots are only slightly warm and have a nice warm white light. The connection is made directly without a transformer at 230 V.
