Nke mbụ unit bụ otu ihe na nke abụọ.Ọ bụrụ na gbakwunye mmiri mgbe ahụ enwere ike iji unit wepụ ntụ ntụ mbipụta.Nke abụọ unit bụ a atọ rola imewe, nke rọba rọba nakweere akpan akpan ihe nke mere na ọ nwere ike evenly uwe ngwaahịa na ezi mmetụta.Na ọ dabara maka mmiri na-adabere na mmanụ / mmanụ na mmanụ na-egbuke egbuke, wdg. Enwere ike ịhazi unit ahụ nke ọma na otu akụkụ.