The FAIWBS75 Wire Cup Brush has the following specifications: 
Face Diameter: 75 mm. 
Shaft: 6 mm (1/4in). 
Wire: 0.3 mm crimped steel wire. 
Conforms to ISO 9001. and DIN EN1083-1 and 2.
This Faithfull crimped steel Wire Cup Brush is designed for light to medium-duty applications, such as cleaning metal surfaces prior to welding or painting.
  The wire brush is fitted with a 6mm (1/4in) shank and is designed to operate with power tools with a maximum speed of 4,500/min.
  Type: Cup.