  We give a variation of McShane's identity, which describes the cusp shape of
a hyperbolic 2-bridge link in terms of the complex translation lengths of
simple loops on the bridge sphere. We also explicitly determine the set of end
invariants of $SL(2,\mathbb{C})$-characters of the once-punctured torus
corresponding to the holonomy representations of the complete hyperbolic
structures of 2-bridge link complements.
