Unusually small scale enamel 'fausse montre' (false watch) c.1770. 
Possibly part of a 'toy' chatelaine. In the c18th 'toy shops' supplied all manner of trifles to provide amusement and such chatelaines were part of the thriving luxury retail market for the fashionable British 'beau monde'.
Copper gilt mounts and hanger,the reverse enamelled with 'wrigglework' on a green ground.
1 inch diameter.