After much internet research I came across this board sleeve of Schneider. She was compared to other models "inexpensive". The Bohbild fit to the thread diameter. What the hell, I thought, then I replace just the screws. This part is very massive, unfortunately, the disk is not 100% level, therefore only 4 points. The delivery via Amazon known quickly and without any complaints.
This ground socket fits among others for the sunshade / umbrella Siena Garden Montego Ø 350 cm, I have replaced the 10 mm screws from Siena Garden from 8 mm screws from the hardware store, because the ground sleeve has only 8mm thread. The hole pattern fits exactly to the Aufschraubplatte of Siena Garden. Who wants it perfect can extend the 8 mm holes in the ground socket to 10 mm thread. I just wanted to give the information, because there is no official Bodenülse for concreting of Siena Garden ;-)
