With knurlingSurface: Chromed, polishedDIN 3124, ISO 2725-1Made In GermanyDrive: Square 12,5 mm (1/2 inches)Output: Outer hexagon traction profileKey width: 19 mmDimensions / Length: 38 mmDiameter d1 (on the output):26.6 mm Diameter d2 (on the drive): 23 mm Net weight (kg): 0.07 kg For manual operation * = Outside the DIN range