Privacy filters differences MBP & MBP Retina display.

Hi everyone.

I was looking for a privacy filter for my 2011 MBP 15 inch but I can find it in my country. So I find it in Amazon and eBay but I don't know about the difference between the Retina Display privacy filter and the another one for the old MBP's. So, it's any difference or it's only the price the difference?

Thanks for your answers!