Kutsogolera pawirizida za nyongolotsi ndi gudumu nyongolotsi ndi mtundu wa zida dongosolo ntchito kufala mphamvu. Zimapangidwa ndi nyongolotsi, yomwe ndi wononga ngati cylindrical chigawo chokhala ndi mano a helical, ndi gudumu la nyongolotsi, yomwe ndi giya yokhala ndi mano omwe amalumikizana ndi nyongolotsi.
Mawu akuti "dual lead" amatanthauza mfundo yakuti nyongolotsi ili ndi mano awiri, kapena ulusi, womwe umazungulira pa silinda mosiyanasiyana. Kapangidwe kameneka kamapereka chiŵerengero cha magiya apamwamba kwambiri poyerekeza ndi nyongolotsi imodzi yotsogolera, kutanthauza kuti gudumu la nyongolotsi lizizungulira nthawi zambiri pakusintha kwa nyongolotsi.
Ubwino wogwiritsa ntchito nyongolotsi ziwiri zotsogola ndi gudumu la nyongolotsi ndikuti zimatha kukwaniritsa chiŵerengero chachikulu cha gear pamapangidwe ophatikizika, ndikupangitsa kuti ikhale yothandiza pakugwiritsa ntchito komwe malo ali ochepa. Komanso ndi kudzitsekera paokha, kutanthauza kuti nyongolotsi imatha kugwira gudumu la nyongolotsi m'malo mwake popanda kufunikira kwa brake kapena makina ena otsekera.
Mitundu iwiri yotsogolera nyongolotsi ndi magudumu a nyongolotsi imagwiritsidwa ntchito kwambiri pamakina ndi zida monga makina otumizira, zida zonyamulira, ndi zida zamakina.