The metro style password field is very similar to the Text Box (Text Input Field) in its design. The look is very similar and it also has a button to the far right of the control.
This time instead of clearing the field, pressing the button will reveal the text you’ve just entered which is by default masked. This is useful, especially for long passwords and while entering the password through touch instead of a keyboard, which is less error prone.
So here are the screenshots of the light and dark theme of the Password Box JMetro skin implementation: