Igiti cyinzoka nikintu cyingenzi mubisanduku byinyo, nubwoko bwa garebox igizwe nibikoresho byinyo (bizwi kandi nkinziga yinyo) hamwe ninzoka yinyo. Inzoka yinyo ninkoni ya silindrike yashizwemo umugozi winyo. Ubusanzwe ifite umugozi uhindagurika (inzoka yinyo) yaciwe hejuru yacyo.
Ubusanzwe inyo zikozwe mubikoresho nk'ibyuma, ibyuma bidafite ingese, cyangwa umuringa, bitewe nibisabwa kugirango imbaraga, igihe kirekire, no kurwanya kwambara. Byarakozwe neza kugirango bikore neza kandi bikwirakwizwa neza muri garebox.