Logic Masters Deutschland e.V.

Normal Sudoku rules apply.
Digits separated by an X sum to 10.
A digit in a circle is the number of circles with that digit.
Digits along arrows sum to the number in the attached circle.
All arrows are length 2 and do not turn.
Arrows from odd circled digits travel horizontally.
For circles in columns 1-4, the arrows point to the right.
For circles in columns 6-9, the arrows point to the left.
For circles in column 5, there are no arrows.
Arrows from even circled digits travel vertically.
For circles in rows 1-4, the arrows point down.
For circles in rows 6-9, the arrows point up.
For circles in row 5, there are no arrows.

Try "Invisible Arrows" here:
SudokuPad