Pros - Easy to install and remove - Magnetic adapter ring is compact enough to leave installed on lens - Magnets work with other brands of magnetic lens caps and filters Cons - Circular polarizer filter sometimes doesn’t seat itself fully flat on the adapter ring, need to press down firmly to ensure a flat install - Magnetic adapter ring doesn’t have any thread or place for a lens cap to grip, so lens caps fall off easily This circular polarizer system is a great way to quickly add or remove a filter. The magnets hold well and also allow the polarizer to rotate smoothly to make adjustments for optimizable polarization. I also have some Kase brand magnetic filters and lens caps that work with this system, and that was a nice bonus that they’re compatible. The adapter ring doesn’t have any threads on it to help a spring-loaded lens cap to grip. That means lens caps will fall off easily when attached to just the magnetic adapter ring. The solution is to either install the circular polarizer filter with the lens cap or buy a separate magnetic lens cap that can attach directly to the adapter ring. Personally I like the magnetic lens caps. As with any circular polarizer filter, you will lose some light and will need to compensate to brighten your exposure back to normal.