I bought this to use some of my Canon and 3rd party EF lenses on an Olympus E-M1 Mark II camera. As I have most general lenses for the E-M1 I really only needed it for 2 of the EF lenses, one a Tamron 150-600 and the other a Canon 100mm Macro. Both worked properly with this adapter and I was able to get good sharp and very usable photos with it. However there are some restrictions with this adapter that should be mentioned.One, this is a "dumb" adapter in that it has no electronic components and thus there is no communications between the lens and the camera. That means that auto-focus, aperture adjustment and lens stabilization will NOT work. If you need those you need to look for some of the more expensive converters that contain electrical connections.Two, your camera will not know a lens is attached so you need to make sure you can shoot "without a lens".Third, since your lens becomes a strictly manual lens you can not adjust the aperture from the camera and you will either end up shooting wide open or you will have to set the aperture of your lens with the native camera for the lens and then find a way to dismount the lens without resetting the aperture. I do this with the DOF button on my Canon.Lastly, you have to be prepared to focus manually. If your camera provides "focus peaking" you might want to use that to get your shots in proper focus.If you are prepared to use your camera with the above restrictions this is a great little adapter and I have been able to use my EF lenses to good advantage and been very please with the results. The adapter seems solid and well made, but comes without any case or end caps to keep it clean and undamaged. Mine came in a plastic bag and I now store it, in my camera bag, in that plastic bag or leave it attached to one of my EF lenses in the lens case. Since this adapter fits an EF lens on one side and a M4/3 camera on the other you probably can also buy an Olympus lens end cap and the Canon camera body cap. That is what I plan to do to keep this clean.