Abstract: A well bore communication pulser in a shuttle package is arranged to aid in stabbing the package into the muleshoe receiving bore in the drill string, especially when the muleshoe is located in a drill string bore larger than the upwardly continuing bore of the drill string from which the package arrives when being installed. The shuttle package is provided with at least two elastomer centralizers separated along its length with the lower one just above the muleshoe after the package is stabbed into its bore. When the drill string is inclined relative to vertical the package sags in the span between the centralizers. The sag lifts the lower end of the package toward the drill string centerline by fulcrum action of the lower centralizer.