Jefa rudder bearing consists of a black anodized, high strength aluminum bearing housing, which, depending on the rudder stock diameter, will have either one or two rows of captive roller bearings. The roller bearings provide an exceptionally low-friction co-efficient, typically 1/10 of that of a plain bronze or plastic bush. They do not suffer from absorption, which often causes problems on plain plastic bearings.
The self aligning version of the Jefa bearing has a similar construction, with the exception that an additional Delrin ball fits between the roller bearing and the anodized aluminum housing. The Delrin ball moves in a spherical seat which allows up to +/- 4 degrees of the angular deflection between the rudder stock and its bearings.