Light-Duty Brush - without Rod Fine wire for light rust spots in steel tanks or Bayerite deposits in aluminum models. Will not seriously damage the interior coatings of aluminum tanks. Special, small stainless brushes for removing those stubborn deposits on the very bottom of dive tanks. Each brush screws onto a 3-foot aluminum rod which fits into any 3/8 electric drill. Each unit comes with the brush and a plastic guide sleeve to augment insertion through tank necks.