Privacy window film - one way mirror effect?

I'm looking to apply the Silver Vinyl Adhesive 'Privacy Film' to my lower ground floor windows.

Basically it creates a mirror effect on one side of the glass (so the public can not see in) and transparency is kept on the other side (so i can see out).

I'm not exactly sure what the technical name for it is?

Does anyone know where i might find this... and who might apply it to my windows?