I bought the PGYTECH filter kit for my P4P and they are of excellent quality!
6 filters in total: UV, ND4, ND8, ND16, ND32 and Polarizer and a very nice case to carry.
The constructive quality is better than the original ones (which i have) and is equivalent to PolarPro (thai i had).
They look good. I like the fact that you are getting a number 4 for flying right before dark! 6 filters for 79.99 is great if they are Polar Pro quality!