Yuav ua li cas laum qhov conical qhov ntawm MS & SS phaj? Peb muaj peb kauj ruam, peb xaiv peb qhov tshwj xeeb qhov khoom siv txhawm rau txhawm rau phaj, uas siab tshaj plaws tuaj yeem yog 20mm tuab. Piv txwv li, thaum peb laum ib phaj nrog 20mm tuab, thawj zaug peb siv qhov nruab nrab qhov me ntsis txhawm rau txhawm rau qhov tob ntawm 18mm, tom qab ntawd siv me ntsis tho me ntsis los laum 2mm phaj kawg, thaum kawg siv qhov loj me ntsis txhawm rau ua rau lub qhov taub loj dua mus txog qhov tob ntawm 10mm. Tau kawg cov phaj tuab yog raws li cov neeg siv khoom xav tau, peb siv cov khoom ntshuam me ntsis, uas tuaj yeem pom hauv khw hauv Suav teb tsis tshua muaj, yog vim li cas peb thiaj tuaj yeem ua lub qhov taub rau peb cov neeg siv khoom.