YB-12 / 0.4 isanduku yubwoko bwisanduku (hejuru na voltage ntoya yabanje gushyirwaho) ni amashanyarazi menshi, guhinduranya imashini hamwe nogukwirakwiza amashanyarazi make, ukurikije gahunda imwe yo gukoresha insinga yatunganijwe murimwe muruganda rwabigenewe imbere kandi ibikoresho byo gukwirakwiza ibikoresho byo hanze, ni ukuvuga, transformateur kumanuka-hasi, gukwirakwiza voltage nkeya nibindi bikorwa bihujwe hamwe. Yashyizwe mubushuhe, butagira ingese, itagira umukungugu, irwanya imbeba, irinda umuriro, irwanya ubujura, izirinda ubushyuhe, ifunze neza, agasanduku k'ibyuma byimukanwa, cyane cyane bikwiranye no kubaka imiyoboro yo mu mijyi no guhinduka, ni insimburangingo nshya nyuma izamuka ry’abasivili. Isanduku yo mu bwoko bwa sanduku ikwiranye na mine, inganda zinganda, peteroli na gaze hamwe na sitasiyo y’umuyaga, isimbuza icyumba cyambere cyo gukwirakwiza abaturage, sitasiyo y’amashanyarazi, kandi ihinduka igikoresho gishya cyuzuye cyo guhindura no gukwirakwiza.
Urutonde rwa YB rwashyizwe hamwe rufite ibiranga imbaraga zuzuye zuzuye, ingano nto, imiterere yoroheje, imikorere yizewe kandi yizewe, kubungabunga byoroshye, no kugenda, nibindi. gusa 1/10 ~ 1/5 cyibisanzwe bisanzwe, bigabanya cyane imirimo yimiterere nubunini bwubwubatsi, kandi bikagabanya ibiciro byubwubatsi.