Bestar na-enye usoro zuru ezu nke akụkụ ọnụ ụzọ ala na ngwa. Nke a na-agụnye niile ala ụzọ ngwaike na ngwa dị ka torsion iyi, spring mwekota, drum, ndoli yinye, lash, Central mkpọchi, ihu igwe, stapler, atụdo, aro tube…