I saw in the characteristics of this product that it worked with the ASUS. Considering it costs 2x cheaper than that sold by ASUS Accesssoire, so I ordered.
I therefore confirm its perfect compatibility with ASUS Zenbook UX21 my hip on a VGA projector.
Picture perfect, no flicker, colors met. To summarize, I see no difference with that provided by ASUS.
A buy eyes closed.
I'll order another one as soon as I rescue.
PS: The output of VGA Video Zenbook is on hold to right (under the power input). The other micro HDMI socket on the left is for the HDMI Normal.