Cov iav qhov rooj tsis yog tsuas yog zoo nkauj xwb tab sis siv tau ntau dua thiab ruaj khov; Raws li kev kos duab thaum ub, iav qhov rooj hluav taws yog qhov ruaj khov dua li cov qhov rooj zoo tib yam ntawm kev ua tau zoo, tsis tsuas yog tsis muaj deformation thiab cracking teeb meem, tab sis kuj nrog high-tech locks, anti-tub sab tub nyiag, zoo dua lub teeb kis tau tus mob kev ua tau zoo thiab ntev kev pab cuam lub neej.