An adapter comprises a generally cylindrical adapter, engagement member bores, retention member bores, and an attachment structure configured for allowing the adapter to be fixedly attached to a mating portion of the drilling head equipment. The engagement member bores extend effectively parallel to the central bore. The retention member bores are each adjacent a respective one of the engagement member bores. The retention member bores are positioned such that the engagement pin bores and retention member bores intersect. The retention member bore is configured for having a retention member engaged therein in a manner allowing the retention member to be selectively displaced along a length of the retention member bore. The adapter includes a central bore to accommodate a down hole tubular. The attachment structure includes a surface adjacent the central bore comprising fastener bores substantially parallel to the central bore for facilitating connection of the adapter to the drilling head equipment.