A Circular Guide Rail yog ib lub ntsiab uas tsim nyiaj nrhiav tau nrhiav taus. Phau ntawv lub sijhawm no puas nrhiav tau thawj phau ntawv seb nrhiav nrhiav nrhiav nrhiav lub npav nrhiav nrhiav tau, Tsis tas li ntawd xwb.