Aia ka ʻōnaehana kākoʻo uwea me ke alapiʻi uwea, ka pā uwea a me ke ala uwea.
Wahi a nā mea hana, ua māhele ʻia i ke alahaka metala a me ke alahaka plastik, ke aniani fiber reinforced plastic bridge etc. E like me ka hoʻolālā, ua māhele ʻia i ke alapiʻi uwea, ke kīwī uwea, ke kahawai uwea , loaʻa iā lākou nā pono a me nā hemahema: ka He maikaʻi ka hoʻokō ʻana o ka ventila, akā ʻaʻole i ka lepo a i ʻole ke keakea ʻana, ʻo ke ʻano o ke kahawai he lepo-hōʻoia, anti-interference, akā maikaʻi ʻole ka hana hoʻopau wela.Hoʻohana nui ʻia ka pā kelepona no nā wili i hōʻike ʻia i nā hale ʻoihana a me nā hale kīwila.ʻO kēlā me kēia ʻano o nā ʻōnaehana kākoʻo uwea i loaʻa i nā ʻāpana pololei, nā ʻāpana piko, ke kahawai strut, nā mea hoʻohui a me nā mea pono.ʻO Vertical Left Bottom Elbow kekahi o nā mea i hoʻohana mau ʻia ma ka ʻaoʻao hema.