ʻO ke kila ʻāpana H he ʻāpana hoʻokele waiwai a me ka ʻike kiʻekiʻe me ka ʻoi aku ka maikaʻi o ka māhele ʻāpana ʻāpana a ʻoi aku ka maikaʻi o ka ratio paona ikaika.Ua kapa ʻia ʻo ia no ka mea ua like kona ʻāpana me ka leka Pelekane "H".No ka mea ua hoʻonohonoho ʻia nā ʻāpana a pau o ke kila ʻāpana H ma nā kihi ʻākau, loaʻa i ka ʻāpana H-section nā mea maikaʻi o ke kūpaʻa kūlou ikaika, ka hana maʻalahi, ka mālama ʻana i ke kumukūʻai a me ke kaumaha o ke kūkulu ʻana ma nā ʻaoʻao āpau, a ua hoʻohana nui ʻia.