Razor hlau, tseem hu ua rab chais barbed hlau, yog ib yam tshiab ntawm kev tiv thaiv cov khoom tsim nyob rau hauv xyoo tas los no nrog muaj zog tiv thaiv thiab muaj peev xwm cais tawm.Cov ntse riam-puab pos yog buckled los ntawm ob lub xov hlau thiab tsim rau hauv ib lub concertina zoo, uas yog ob qho tib si zoo nkauj thiab txias.Ua si muaj kev cuam tshuam zoo heev.
Cov chais hlau muaj cov yam ntxwv zoo xws li cov tsos zoo nkauj, kev lag luam thiab kev siv, zoo tiv thaiv kev thaiv, thiab kev tsim kho yooj yim.