Extensions with Archimedean ramification points

A subgroup of the Galois group of an extension of an algebraic number field that is closed with respect to 2-extensions is considered. This subgroup is generated by the inertia sub-groups of the real points of the maximal real subfield. It is proved that this group is the free product of the Cantor set of cyclic groups of order 2 in the category of pro-2-groups.