 The Flip tool provides the ability to flip
      layers or selections either horizontally or vertically.
      The Flip tool provides the ability to flip
      layers or selections either horizontally or vertically.
    
|  | When flipping selections, a new layer will be created and the old layer that the selection was created on will have that area "cut" from it. | 
Flip Tool Settings
The Tool Toggle settings control flipping in either a Horizontal direction or a Vertical one. This toggle can also be switched using a key modification.
Default Keyboard Shortcut: Shift-F
Key modifiers:
Ctrl toggles the flip direction.