Ko ngā peera roera porowhita he mowhiti o roto me ngā ara reihi e rua e anga ana ki te tuaka peera, he mowhiti o waho me te ara reihi porowhita noa, ngā roera porowhita, ngā whare herehere, ā, i ētahi hoahoa, me ngā mowhiti arataki o roto, ngā mowhiti pokapū rānei. Ka taea hoki te hiri i ēnei peera. Ko te nuinga o ngā peera roera porowhita he mea hanga ki ngā rarangi roera e rua, e āhei ai rātou ki te kawe i ngā kawenga radial tino taumaha me ngā kawenga axial taumaha. He hoahoa anō hoki me te rarangi roera kotahi, e tika ana mō ngā kawenga radial iti ake, ā, kāore he kawenga axial.
Ko ngā whāriki mīhini pepa he wāhanga mīhini pepa.
Ko ngā peera mīhini pepa, he peera kua whakakīia ki tētahi hinu whakahinuhinu totoka motuhake e whakarato ana i te hinu whakahinuhinu tonu mō te whakahinuhinu mō te wā roa.
Ko ngā peera roera porowhita te mea nui o te hoahoa, inā koa ka tīpakohia ngā peera nui me ngā peera rahi-waenga.
