You should know why one buys this product ...

Certainly, it is not very strong (critical [justified] raised in some comments: it has already torn [a tiny hole, caused by the fact that the plastic is stuck between the viewfinder eyepiece and the eyepiece] by trying around the opening to the viewfinder, but just reinforce plastics with wide tape), but it's not expensive and it's absolutely what I need to insulate my device Photo from rain, moisture, sand or screenings dust and other wind ... I will go on a trip in a few months in an area at risk for cameras; I am happy to have this product to protect them.
For my needs, no need to have a "trick" sophisticated, it is true that I have not tested it in condition, but this seems quite suitable for my use and that's all I asked. Moreover, given its price, if it rips, it's not a big deal ... and seen what I've tested, I do not think he can tear a way that does not fulfill its Office in due course. In addition, there are two in the package ...