Ko te tirohanga matapo e kiia ana ko te mea he rite te ahua o tona ahua ki te nama "8". Ko tetahi pito he matapo me tetahi atu pito he mowhiti rino. Heoi, ko te diameter o te mowhiti throttingling he rite ki te diameter o te putorino me te kore e mahi i te mahi throtting. Ko tenei hoahoa e whakaatu ana i te tirohanga matapo i te tino ngawari me te whai hua i roto i te punaha paipa.
