Rear wheel pack (incl. 3 sealed non-ABS and 1 sealed ABS bearing). Dimensions: 25mm ID x 52mm OD x 15mm deep. Replacement for OEM 9276A / 9276B and 9252A / 9552B. Note: These All Balls Racing sealed ball bearings are high quality high speed wheel bearings. Manufactured to ABEC 3 precision levels. Bearings are lubricated with a Chevron fabricated high performance; high temperature grease of SRI 2 level that contains anti-rust and anti-oxidation additives. Compatible with temperatures of -20°C to +150°C and rotational speeds in excess of 10.000 RPM. Triple lip seals are used to help prevent water and debris entering the bearing.