Gets stuck on my lens very easily
355050
The filter looks nice and with great packaging but gets stuck immediately on my lens with only light tightening applied and hard to remove, applied after both the lens and the filter were in the same room temperature, I am returning it sorry but cannot struggle to remove it when I am taking pictures
1085557
The ring is what it says it it, but it did get stuck on my camera and took quite an effort to remove it without damage to the threads. Worked well for reversing the lens for macro shots. It is metal, and is well made, but the threads seemed off a bit and it fits a tad bit too tightly
3231369
Seems like a good lens but the snap on/off mechanism is annoying and too risky for competition
3448697
I couldn't get it to stay on affixed it to the mask lens.  I sent it back and am still waiting for a refund.
2104408
I've not had  a problem of getting it off the camera or lens but you really need a tripod o get the most out of it
4426362
I bought this UV filter to protect the 50mm f/1.8 canon lens that I purchased.  While I can't aruge with the price, I didn't like the way it fit on the lens.  I tried screwing it on carefully multiple times but could never get it to sit flush against the lens.  It always seems like one side stuck out a bit.  That being said, I haven't had any problems with it falling off when I take the lens cover off so it's not too bad.
1893089
Lens release button seems to stick, unable to remove from my 50/1.4 -- any tips to remove?

Otherwise works exactly as advertised, includes clear instructions to enable the camera to overcome "no lens attached" issue reported by others.

However, fusing permanently to your favorite lens is a deal breaker...
532527
This morning, my camera fell and hit pavement directly on the lens.

I had this UV filter in a closest since 2011. For some reason, two weeks ago I stuck it on my Sigma 30mm.

The glass on the UV protector shattered, but the lens seems fine. It took me a while and some serious force to get it off because of the impact.

I just ordered two more.
3011058
I have purchased two of these over the past year. Sadly they are extremely easy to lose. I carry my camera in my schoolbag with me and somehow I have managed to lose two of these eye pieces. The first one I received was actually a little rubbery around the eye which I enjoyed in case someone bumped me when I was taking a photo but the second one I purchased was just plastic. I feel a little more concerned that I might bruise my eye if I am bumped but for the price I cannot really complain. I took off one star for the pieces ability to be easily lost by me.
2283919
Unfortunately I'm not too impressed.  Once on my 150mm Macro len's Hoya 72mm filter, it simply would not come back off... Which would have been fine if I didn't need to mount my macro flash on the filter.  A bunch of my friends attempted to unscrew it to no avail.  Finally one friend was able to remove it.  I won't be using this thing again.
853710
The rings that are supposed to have adhesive on them to stick to the camera and then you magnetize the lens to the camera are not sticky.  There is no way to secure the lens to the camera.
2568507
Compared to my Nikon lens caps, the springs don't have as much pressure and the serrated teeth that hold it into the lens are pretty flat. This cap pops off the lens without even touching it. One good bump on my 80-200 and the cap flies off. I literally cannot pry the Nikon caps off my other lenses with moderate fingertip pressure. I guess there is a reason they sell it with a lanyard. Also, there is a tiny hole -- maybe 3/32 of an inch -- in one edge of the front of the cap, I suppose to attach the lanyard. Personally, I like lens caps to keep dust and debris off the lens, and this hole is going to let some in, though admittedly very little. One positive note-- it does say "Nikon" and look about like an OEM cap.
2300984
Love it, but it keeps falling off of the lens when I take it out of the camera bag. It almost fell into the Grand Canyon.
3860478
The locking pin doesn't go back up completely for me so it got stuck on my Fuji X100S. The screws are really tight so I could only open one and destroyed another one so I had to break open the top to release the pin. Be careful.
557307
As mentioned by other people, this sticks too tightly onto lenses - not in a good way. The pin is junk.

Buy something else unless you want to risk totally ruining a lens forever.
745035
This causes it to twist off too easily.  It may work better for a different camera but I wouldn't recommend it for the Nikon Df.
3802596
I bought this step up ring so I could have one set of filters rather than buying a second set for my other lenses. I put the step up ring onto my lens and gentle screwed the filter into it making sure to not tighten it up since I saw some say they actually had filters get stuck.. well I went to remove my filter and the ring and filter both came off the lens. Tried to separate but filter is stuck.. Got a set of filter wrenches coming hopefully will resolve my issue..