Wise-libra has described it correctly. On the lamp side, the device is held in place by inserting the tube into the lamp, no additional fastening is necessary or provided. On the cup side/rosette side, various possibilities are conceivable. Possibilities are conceivable. 1-2 drill holes (1 should be enough) or possibly just sticking it on (e.g. Tesa Powerstrips or similar). The element is not heavy.

We have now maintained the data. The fixture is only attached to the hole (in the ceiling) and where the luminaire is hung. This should also be indicated in the pictures.