Nke a bụ ite ntụ ntụ polygonal nke nwere ihe dị ka 5g, nke dabara adaba maka iji ntụ ntụ, ntụ ntụ anya, isi ntụ ntụ na ngwaahịa ndị ọzọ. A na-eji plastik mee ngwaahịa ahụ dum, a na-efesakwa mkpuchi ya na ọgwụgwọ plain, nke nwere ike ime ka ngwaahịa ahụ dum yie nke ọma. Opekempe kacha nta bụ 8000, ma ruo n'ókè kacha nta, enwere ike ibipụta ụghalaahịa.