Heavy duty cast iron spanner. Durable, torsion-resistant construction. Double-ended bone format reaches nuts in tight places. Corrosion-resistant powder coating. Fits 1/2″ and 3/4″ tap back nuts. Heavy duty cast iron spanner. Durable, torsion-resistant construction. Double-ended bone format reaches nuts in tight places. Corrosion-resistant powder coating. Fits 1/2″ and 3/4″ tap back nuts.