Izinto zikagesi zekilasi I azibambi iqhaza ohlelweni oluthile lokugreda.
Okokusebenza kukagesi kweClass II, ukuhlukaniswa kunqunywa uhlobo lwegesi evuthayo okuhlangabezane nayo. Le mishini iphinde ihlukaniswe yaba izinhlobo ezintathu ezivikela ukuqhuma: IIA, IIB, kanye ne-IIC.
Ezindaweni ezisebenzisa izinto zikagesi zeClass I, lapho amagesi avuthayo ngaphandle i-methane akhona, ukuthobelana nawo womabili amazinga e-Class I kanye ne-Class II okuvikela ukuqhuma kuyisibopho.
Ngokusekelwe ezicini ezithile ze- eziqhumayo imvelo yothuli, Izinto zikagesi zeClass III zihlukaniswe izigaba ezintathu: IIIA, IIIB, kanye ne-IIC.