O tulimanu faʻafesoʻotaʻi o polo e masani ona tele avega avega unidirectional.
O le sili atu le faʻafesoʻotaʻi le itu, o le sili atu o le aveina gafatia. O le pa mea o uamea ipu, apamemea po o inisinia palasitika, ma lona fausiaina metotia o stamping pe liliu, faʻalagolago i le ituaiga o le fanauina po o tuutuuga o le faʻaaogaina.
E i ai isi tuʻufaʻatasiga o angular contact ball bearings, double row angular contact ball bearings ma fa-point contact ball bearings.
