Due to manual measurements, please allow a 0.1-0.5 inch difference. (1 inch = 2.54 cm)Specification:Material: SteelColor: BlackSize: 88mm*22mm/3.5"*0.9"Batch head diameter: 12.5mm(1/2")Hole diameter: 6.3mm/0.25"Usually fit 6mm batch headPackage Included:1 x 1/2" Electric Wrench ConverterWe have commodity security services. If the product you received has quality problems, please feel free to contact us, we can provide you with a return service.