These are good covers, they're not quite as smooth to operate as canon oem, but they do fit and work fine.

I thought the retainer jaws would be internal, with nothing extending to the rim that could be knocked and release the caps. Not so - there are finger grab recesses in the face, but the moving part extends clear to the outer perimeter and can be inadvertently released with a fairly light touch. Not so good in a pack or on a brushy trail where you really don't want the cap to come off, even if it is secured with a leash.

The media could not be loaded. Pretty straightforward. You get what's stated and it fulfills the purpose. The lens cap for my camera had a little plastic piece snap off and render it useless. Found these as a replacement and they fit perfectly for my camera. The string to loop it to my camera is a little long. But better longer than shorter.

Pros:
+Relatively durable
+Long string for looping to camera
+Comes exactly as stated
+Fits my Nikon's 18-55mm lense

Cons:
-Very plain(might not be a con)
-Not very smooth(Some slight clicking/friction sounds when squeezing it)
-Edges are a little sharp(most of the time, you likely won't mind it too much though)

Overall, pretty satisfied. Would buy again. I just don't break caps very often.

The cap part works very well, better than the original Canon in one sense but not another. I've had the Canon caps fall off because I didn't get them installed properly (one advantage of the Canon cap, though is that when it does fall, so far it always lands outside-down). With these caps, the threads engage more easily, and a quick tug on the cord ascertains that they won't fall off. On the other hand, the finger-gripper recesses are not as well designed as the Canon ones, and your fingers tend to slip out more easily, requiring you to bear down harder when either installing or releasing the cap.

What I can't figure out is exactly how to use the cord to hold the cap while shooting. No part of the cord is elasticized; it's just a loop of about 4" (10cm) in diameter. It's too long simply to loop over the lens once; it would likely fall off. It's too short to use that method that is hard to describe in words-I think it's called a saddle-girth tie off--where you loop it over your hand, reach through and grab the other two ends just by the lens cap, and pull through so you have a double loop that can be looped over the barrel and then tightened. That won't work because the only place on the barrel that isn't either the zoom ring or focusing ring is back by the base where it's too far away. I'm thinking of cutting a 1/4" bolt down to where I can tighten it in the tripod socket and looping the cord around that. I may have to cut one end of the cord to get it to reach to the end of the long lens, especially with a hood on it. I tried a simple double loop around the zoom ring. It works ok, but I don't like the idea of trying to frame a shot just right with that thing flopping around against my hand. But that seems to be the only way to make it work easily.

Fits perfect over the lens hood I keep on my Rollei 35s. I use this style of lens cap on all my lenses. Wasn't sure I could get one for the lens hood. This works and fits perfectly. Seller easy to deal with and shipped immediately. Perfect deal.