Introduction:
This Cartier Paris Ceinture is made in 18K White Gold in a classic octagon shape.  The watch measures 25x25mm, Ref. 78100.  Circa 1975-1980. The watch is fitted with a mechanical manual wind 17-jewel movement. 
The watch was rarely available in white gold so this example is just a lovely treasure.
The watch comes with an 18K white gold Cartier Deployant buckle, a black lizard strap as originally equipped, and an extra red lizard strap.  The watch is triple signed:  Dial, Case, Movement.  Additionally, the watch comes with a one year movement guarantee.