Tsis Siv Neeg Bollard
Tsis siv neeg bollards (tseem hu ua tsis siv neeg retractable bollard los yog hluav taws xob bollard los yog hydraulic bollards) yog kev ruaj ntseg teeb meem, ib hom lifting ncej tsim los tswj lub tsheb nkag.
Nws yog ua los ntawm cov chaw taws teeb tswj lossis xov tooj app lossis lub laub khawm, tuaj yeem ua ke rau qhov chaw nres tsheb teeb meem, teeb pom kev, hluav taws kub tswb, daim ntawv tso cai daim ntawv lees paub, lub tsev tswj lub koob yees duab system.
