ProMaster EyeShade لـ Canon Eb, Ef

The soft TPU rubber feels much sturdier than the hard plastic on my old eyecup, and it actually blocks out all the stray light when I'm shooting in bright sun.

The 360-degree rotation is a lifesaver for shooting vertically, and the rubber is soft enough that it doesn't press hard against my eye socket. It seals out light completely, even when I'm squinting in bright sun.

Rotating this thing 360 degrees is way more useful than I expected—I can finally shoot comfortably in portrait mode without light leaks. The soft rubber feels really nice against my eye, not stiff or plasticky like some others I've tried.