1. Feem ntau, peb tuaj yeem faib cov ditch cover rau hauv kub-dip galvanized ditch cover, stainless hlau ditch cover, yas sprayed ditch cover, thiab lwm yam raws li cov khoom sib txawv.
2. Raws li cov duab ntawm lub ditch cover, nws tuaj yeem muab faib ua: lub hau npog zoo tib yam, U-shaped ditch cover, tubular ditch cover thiab openable ditch cover.
