Logic Masters Deutschland e.V.

Rules: Normal Sudoku rules apply. Put the digits 1 to 9 once each into every row, column and box.
Doublers: One cell in each row, column and box is a doubler. The value of a doubler cell is equal to twice its digit. Each of the digits from 1 to 9 appears once in a doubler cell.
Anti-Quads: A digit in a black circle means that none of the four surrounding cells contain that value.
Zipper Lines: Values an equal distance away from the center of a lavender zipper line sum to the value in the centre of the line (marked with a circle).

Links:
SudokuPad: https://sudokupad.app/pch5064ywu