Muab kauv pawg yog ib yam tshiab ntawm cov khoom siv yooj yim lub tsev, uas tuaj yeem hloov tau ib feem ntawm cov tsoos reinforced pob zeb nchuav ua kev tsim kho tshuab, ua lub hauv paus tsev hloov tau yooj yim dua thiab ceev dua. Nws tshem tawm cov nqi kev tsim kho xws li theem hauv av, khib nyiab kev kho av thiab khawb, thiab tuaj yeem siv dav hauv kev tsim kho hauv ntau hauv kev lag luam.
