This is a great concept but needs a little improvement. Personally I find it to not work well on my Vortex Vipers which have a soft runner edge on the eye cup. When you clamp the magnet to the eyecup it squishes and allows it to work itself off. If the clamp was a bit deeper or if your particular binos had a firm/hard eyecup then it would probably work perfectly.
Their CS is responsive and they are willing to help with return or exchange. I am going to see if I can make it work somehow. Or save it for a different pair of binos.