Vac-U-Lock - Grote zwarte zuignap plug

That suction cup base holds way better than I expected, even on the tile wall in my shower. I've got one of the bigger attachments and it stays put without any wobble, which is exactly why I upgraded to this jumbo version.

Wasn't sure the suction would actually hold something this big, but it locked onto the tile and didn't budge. The base is noticeably wider and sturdier than the standard cup, which makes a real difference on larger attachments. Worth paying a bit more for.

Finally upgraded to the jumbo base and the grip is no joke—it hasn't budged on my tiled shower wall through a full session. The extra-wide surface area feels way more stable than the standard size I used before.