1. Muaj ntau lub cores, txhua qhov dej qhuav thaiv cov qauv, tsis muaj tshuaj pleev, huv si thiab ceev thaum lub sijhawm tsim kho, thiab tsis muaj kev cuam tshuam rau ib puag ncig.
2. Cov iav fiber ntau reinforced yas pas nrig (FRP) qhov chaw txhawb nqa.
3. Cov yeeb yaj kiab ob sab uas tau qhwv ntev thiab npog nrog daim kab xev hlau corrugated tuaj yeem txhim kho qhov kev tiv thaiv siab ntawm cov xov hlau kho qhov muag.