A sun visor includes a screen slidably mounted over a shaft attachable to a vehicle. A guiding profile is mounted in the screen, and a slider is rotatably mounted over the shaft and housed inside the guiding profile such that the guiding profile can slide longitudinally over the slider to establish a slide on rod function for the sun visor. A detent spring clip is attached to the slider and engages elastically over the shaft of the sun visor such that upon rotation of the screen of the sun visor, it is possible to establish a shading position and an inoperative position for the sun visor. The detent spring clip includes an asymmetrical shape to fit to an asymmetrical core shape of the slider in a single position. The slider includes an asymmetrical external shape to fit to an asymmetrical internal shape of the guiding profile in a single position. The guiding profile includes an asymmetrical external shape to fit to an internal shape of the screen in a single position.