Iibhokisi zolawulo ziyilelwe ukuqinisekisa ukuba izixhobo zibekwe ngokukhuselekileyo kwaye zikhuselwe kwiindawo ezirhabaxa, ezifanelekileyo ngokufanelekileyo ukuba zisetyenziswe kwindawo yoshishino okanye enokuba yingozi.Iindawo ezivaliweyo zifumaneka kuluhlu lwezinto, imibala kunye nezitayela, kubandakanywa iplastiki, i-aluminium kunye nensimbi engenasici ukuze ihambelane noluhlu olubanzi lwezicelo.