Ntev-ntev peb-phaj folding rov qab ib feem, 1st folding kab yog 180 °, 3rd folding kab muaj 135 °. Nws yog siv los qhib lub thawv yooj yim. Lub segmented qaum siv phaj ua ke nrog cov qauv tsim tshwj xeeb tuaj yeem hloov kho raws li qhov xav tau ntawm cov khoom, muab qhov chaw rau kev teeb tsa tshwj xeeb lub thawv-hom khoom siv.