An improved design. - Vortex Defender Flip-Cap Lens Cover

I've got these on a 2nd gen Vortex Viper PST 1-6x24. As recommended by Vortex, I'm using an E-10 on the eyepiece and O-24 on the objective. They are quite nice. They're a flexible, stretchable, rubbery design. The rubber boot is quite grippy, and can take a little finesse wiggling it on to your optic. Once you've squeezed it all they way on, the cap area butts up against the scope tube. The cap area is a hard plastic molded seamlessly to the rubbery boot. It's an interesting design and I definitely think it's an improvement on the classic Butler Creek caps. The stretchy rubber is going to be much less prone to breakage. Also, Vortex has designed some stops in the cap hinge, so you have more options than just opened and closed. The E-10 accepts their dope disk, but just make your own. They want $10 per disk, which seems stupid. I don't like the thickness of the rubber boot, which could cause clearance issues in certain applications (AR optic mounted over BUIS, for example). I don't like the $20 price tag, which seems excessive for rubber and plastic. These things better last a lifetime at that price. And I don't like the figment of the objective cap. The rubber is very...rubbery. By this I mean that when you flip the cap open, the rubber boot starts stretching off where you're opening it from, and your cap points off at an angle slightly. This isn't an issue on the eyepiece for some reason. But the O-24 objective cap doesn't grip tight enough or something. Anyway, it's still far from coming completely off. I still like these better than the old Butler Creeks I typically buy.