3M™ EMS extended range ball marker is specially designed for locating flush mounted facilities that are covered by backfill. It is affixed to the underside of non-metallic lids or covers over flush mounted facilities. This self-align marker offers positive identification of facilities. 3M™ EMS extended range ball marker provides an effective way of marking underground facility lines. It withstands a temperature range of 4 to 122 deg F. This passive underground marker with a water resistant polyethylene shell does not react with any chemicals or minerals. This ball marker effectively operates without the need for any external power source.