Ubu, hari ubwoko bubiri bw'ibinyabiziga bifise amafirigo.
Ubwoko bwa mbere, ni umuduga ushizwemwo, yerekeza ku muduga usanzwe ufise umubiri n’igiti bitandukanye. Izo semi-zikwega zija mu rwego rw’ibikamyo vy’amafirigo, uburebure bwazo bwose hamwe ntiburenze metero zine, uburebure bwose hamwe bukaba metero 13,6, n’ubwaguke bwa metero 2,6.
Ubwoko bwa kabiri, ni umuduga ugabanuka, yerekeza ku muduga w’igice-ufise umubiri n’igiti bishobora gukurwako. Ivyo muri rusangi biza mu bwoko bubiri: kimwe ni ikinyabiziga gifise amagufa c’amafuti 45 (metero 13,95) gikwega ikintu gisanzwe gifise amafirigo, kikaba gifise uburebure bw’amafuti 45 n’ubwaguke bwa metero 2,55.
Ubundi bwoko ni igikoresho gikwega igikoresho gifise amagufa c’amafuti 45-gikwega igikoresho cahinduwe kivuye mu gikoresho co mu kiyaga cakoreshejwe, kikaba gifise uburebure bw’amafuti 45 canke 48 n’ubwaguke bwa metero 2.438. Ubwo bwoko bw’ibinyabiziga vy’ibikoresho vy’amafirigo ubu ni bwo buganzwa kw’isoko. 48-ibinyabiziga vy’amagufa vy’amaguru ntibikiri vyemewe mu Bushinwa.
