Kev sib dhos yooj yim txias rollered steel placon cov menyuam choj tiaj tus sib koom ua ke rau hom 40 cov menyuam taug qab thiab raj
Peb yog cov chaw tsim khoom ntawm steel roller taug kev sib koom ua ke.Peb cov khoom muag ncaj qha los ntawm cov chaw tsim khoom.Nrog tus nqi qis thiab kev xa khoom loj, peb yog qhov kev xaiv zoo tshaj plaws rau cov neeg muag khoom.