Raws li ib qho ntawm feem kev sib tw dai ntawm lub tuam txhab, peb lub teeb lub luag hauj lwm u-straps tau txais ntau lub npe nrov thoob plaws ntiaj teb, tshwj xeeb tshaj yog North America. Tsis tas li, lawv tuaj yeem raug kho raws li koj qhov yuav tsum tau ua, piv txwv li, lawv tuaj yeem tsim nrog roj hmab, ntxig lossis ntaub thaiv. Thiab muaj ntau qhov kev kho mob saum npoo av rau koj cov kev xaiv: Pre-galvanized, Zinc plated, epoxy thiab Green galvanized tiav kom tau raws koj qib sib txawv 'anticorrosion xav tau.