Ko te ngongo whakaheke wera o te pakitara takirua he mea hanga mai i te polymer o te kounga teitei (paparanga o waho) me te whakapiri rewa wera (papa o roto) .Ka tiakina e te ngongo wera te wera ki te makuku me nga taiao kino, i te wa e whakarato ana i te hiko hiko me te tiaki miihini. I te wa o te whakaurunga, ka rewa te riipene aa-ahumahi i roto i te ngongo whakaheke wera ka tohatoha puta noa i te waahi raina ka hangaia he arai whakamarumaru, aukati wai. Ka mātao, ka hanga te paparanga o roto i te paparanga piri i waenga i te ngongo me te wae, waea ranei. Ka whakarato i te hiri-wai me te whakamarumaru mo nga hononga, waea ranei.Ko te pāmahana whakahaere tonu e tika ana mo Minus 55°C ki te 125°C. He karaehe paerewa-hōia me te teitei o te pāmahana mahi o te 135°C. He pai te 3:1 me te 4:1 te owehenga whakaheke.