See also:

Side ventilators
Side ventilators 1) Open 2) Close 3) Thumb-wheel Move the tab to adjust the flow direction. To open or close the ventilator, turn the thumb-wheel up or down. ...

Engine
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Traction AA, A, B, C
The traction grades, from highest to lowest, are AA, A, B and C. Those grades represent the tire’s ability to stop on wet pavement as measured under controlled conditions on specified government t ...