1.Cov roj hmab khiav yog tsim rau excavator drilling rig neeg hlau bulldozer, ect.
2.Cov qauv yog tsim los ntawm ntuj hluavtaws styrene butadiene roj hmab +45# steel hniav +45# tooj liab plated steel hlau.
3. Qhov zoo tshaj plaws ua rau cov khoom ruaj khov, corrosion kuj, aging kuj.