  Let K/k be a finite Galois extension of number fields with Galois group G, S
a large set of primes of K, and E the G-module of S-units of K. Previous work
has determined the data which is necessary to determine the stable isomorphism
class of E. This paper explains how to build a G-module M from this data which
has the property that M is stably isomorphic to the direct sum of E and some
free G-module F.
