Turnouts consist of switch points, points, guardrails, connecting parts, and switch ties. Switch points are used to guide locomotives and rolling stock from the main track to a siding or vice versa; they are made up of a pair of switch rails, a pair of basic tracks, a switch mechanism, and some connecting parts. The switch mechanism, also known as a switch lever, is composed of a lock frame, switch indicator, pull rod, bend rod, etc., to operate the lateral movement of the switch rails and change the turnout's opening direction. Points and guardrails are the transition devices that allow the wheels of locomotives and rolling stock to cross from one rail to another.