Lub luag haujlwm ntawm lub tsev txawb yog muab qhov chaw nyob ib ntus lossis ib nrab mus tas li uas tuaj yeem thauj tau yooj yim thiab teeb tsa hauv ntau qhov chaw. Cov tsev txawb feem ntau yog siv rau kev mus pw hav zoov, vaj tse thaum muaj xwm txheej ceev, chaw ua haujlwm ib ntus, lossis ua kev daws teeb meem rau cov neeg uas yuav tsum tau txav mus los tsis tu ncua. Lawv tau tsim los ua lub teeb yuag, compact thiab yooj yim rau kev sib sau ua ke, muab kev xaiv vaj tsev yooj yim thiab hloov tau yooj yim rau ntau yam xwm txheej.
