The SKF 71906 ACDGB/P4A is a high-precision single row angular contact ball bearing designed for applications requiring high running accuracy and speed. This genuine SKF bearing features a 30 mm bore diameter, a 55 mm outer diameter, and a 13 mm width. The 'ACDGB' designation indicates a 25° contact angle, optimized for high-speed operation and axial loads in one direction. The 'P4A' precision class signifies very high running accuracy, making it suitable for machine tool spindles and other demanding industrial machinery. It is typically supplied as a universal match pair for mounting in tandem, back-to-back, or face-to-face arrangements.