Square Box Npog yog siv nrog cov thawv xwmf los tiv thaiv cov xov hlau sab hauv lub thawv. Ua los ntawm high - Cov hlau zoo steel, cov duab square npog yog tsim kom muaj cov xwm txheej nyuaj tshaj plaws, ua kom ntev} 2}}} kav ntev. Cov ntaub ntawv plaub hau yog qhov zoo rau cov ntawv thov ua haujlwm tau, muab ib qho yooj yim rau cov khoom siv hluav taws xob, hloov dua tshiab, kiv cua, thiab lwm yam.