I am quite new to DSLR photography and as such I was recommended to buy a cover for my lens to help protect it. So if you scratch the lens it would be cheaper to buy a new filter than the complete new lens itself. After some searching I found that a single clear protective filter cost the same (if not more) than this pack of 4.
So I brought this set of Polaroid filters mainly for the clear filter (UV) and the other three were as added bonus. As I am still quite new I can work towards using the other coloured lens at a later date.
I found securing the filter to the lens quite a tight fit, but fitted well none the less. Once on it felt like it wouldn't work its way off.
After using the UV filter for quite a while I found that I hardly noticed the extra cover was on. However, I did find that in extreme light there was sometimes a reflective light flare on the images, as if the picture was taken through a window. So for some photos I found that I needed to remove the filter - but not many.
The little bag that the filters come with is also quite nice to keep them all together.
For the price they are really good value - four filters plus a bag. Like I said I brought this mainly to protect my lens - which is what it has done, so I am very pleased.