Urwego rwicyuma rwicyuma cyinshi rusa nubwa plaque yoroheje.Ku bijyanye n’ibicuruzwa, usibye icyapa cy’ikiraro, icyuma kibumba, icyuma gikora amamodoka, icyuma cy’umuvuduko w’icyuma hamwe n’icyuma cyinshi cy’umuvuduko w’icyuma, amoko amwe y’ibyuma, nk'icyuma gikoresha ibyuma (2.5) ~ 10mm z'ubugari), icyuma cyagenzuwe (2,5 ~ 8mm z'ubugari), icyuma kidafite ingese, icyuma cyihanganira ubushyuhe nubundi bwoko bwambukiranya amasahani yoroheje.
Byongeye, isahani yicyuma nayo ifite ibikoresho.Ibyuma byose ntabwo ari bimwe.Ibikoresho biratandukanye, kandi aho icyuma gikoreshwa nicyuma nacyo kiratandukanye.