Kev ua lag luam tam sim no lub tsheb tawv ko taw mats cov khoom siv feem ntau yog tawv tawv, cov khoom siv ko taw mats xis thiab mos, siab-kawg huab cua, tsis-slip hnav-resistant, yog tus nqi siab ntawm tsheb ko taw mats, yog ib qho kev xaiv zoo rau feem ntau. ntawm cov tswv tsheb.