Vintage Square Nut Wrench Or Valve Key ToolVintage Square Nut Wrench Or Valve Key Tool is a long metal tubular socket wrench with a hollow shaft and a square socket opening of approximately 1. 7 cm at one end. The surface shows overall wear with oxidation and corrosion, scattered rust or brown discoloration, scratches and edge wear. Tools of this form are typically used for turning square nuts or valve fittings. Dimensions: Approx. Width 3. 3 cm, Length 14. 5 cm Condition: Preloved, with