i was told 20% is the same as the back, but once i got it on the front, the 20% film was visually darker than the rears. From the outside, you cant tell because the large amount of light coming in from the front, but on the inside its darker. Id think a 25% would be a better match, maybe 30% but i dont think a 25 is available. Nevertheless, I like my 20%, look in my sig.