content: I bought this because it was cheap. I kept it on the camera all times. When I screwed in a cheap SEIKOS 82mm polarizing filter, it stayed there. The polarizing filter keep turning, but won't come off the TIFFEN UV filter. I had to break the cheap Polarizing filter to find out the thread on the TIFFEN filter was made of plastic and it simply ground away when the SEIKOS filter turned.Now I have to buy both filters new. I am buying a SIGMA glass filter with antiglare coating. Don't buy this cheap filter. spend extra money and get a good brand like SIGMA or CANON.