Kuverenga kwehuwandu hwemvura mune tangi isina kukwana .
Ndapota kombidze hukuru mumamirimita
D - mudziyo dhayamita
H - mvura pamwero
L - kureba kwemudziyo
Chirongwa ichi chichaverenga huwandu hwemvura iri mu tangi ye cylindrical, huwandu hwese uye husina huwandu hwemudziyo, uye nzvimbo dzepamusoro.