SKF 22311EK/C3 spherical roller bearing. Self-aligning double-row spherical roller bearing designed for very heavy radial load with concurrent axial load in either direction, and inherent tolerance for shaft-to-housing misalignment. Two rows of symmetrical rollers ride on a common concave outer-ring raceway. Common execution suffixes cover CC (window-type cage), CA (machined brass cage), EK (tapered bore for adapter-sleeve mount), and W33 (annular groove and three lubrication holes in outer ring). Manufactured to ISO 492 Class Normal / P6. Bore diameter d = 55 mm per ISO 15. Boundary plan per ISO 15 / ISO 355: bore d = 55 mm, outside diameter D = 120 mm, width B (or height H) = 43 mm.