Ko ngā peera pōro e whā-ira-pā he mowhiti o roto e wehea ana kia rua ngā wāhanga. Ka taea e tētahi o ēnei peera te pupuri i ngā kawenga tuaka nui i ngā taha e rua. Ka taea te whakairi motuhake i te mowhiti o waho me te huihuinga pōro me te whare herehere mai i ngā haurua mowhiti o roto e rua. Mā te koki whakapā o te 35° ka taea te kawe i te kaha kawenga tuaka teitei. He pai tēnei momo mō te kawe i ngā kawenga tuaka parakore, i ngā kawenga whakakotahi rānei ina teitei te kawenga tuaka. Kei roto i ēnei peera he whare parahi mīhini.
