  We investigate a mechanical system consisting of infinite number of
harmonically coupled pendulums which can impact on two rigid rods. Because of
gravitational force the system has two degenerate ground states. The related
topological kink - likely the simplest one presented in literature so far - is
a compacton, that is it has strictly finite extension. In the present paper we
elucidate the relation of such system with sine-Gordon model. Also, solutions
describing waves with large amplitude, and an asymptotic formula for the width
of the kink are obtained.
