The kit I received included both foam thicknesses, two light blockers, and the plastic frame which snapped into my Quest 2 with ease.
The thinner foam allows for a closer fit, and therefore a wider view. This foam, however, brought my nose too close to my prescription lens mounting rings, resulting in some discomfort over a period of use. After removing the extra lenses, the interface, although thin, gave a comfortable fit against my face.
When I switched to the thicker foam, the kit provided a good fit with clearance for the prescription lenses. Switching between the two foam pads was easy, as the back of the pads is textured to mate with the plastic frame.
The frame also holds one of the included light blockers for the nose area. The two blockers in the kit were cut at different depths to suit various nose sizes. The larger cutout worked best for me.
The foam is comfortable, even when tightened to the face for longer periods, such as watching a full movie or working through an escape room game. I noticed that after these uses, the markings on my face were less pronounced than after the same activities using the standard interface.
Overall, this is a good upgrade from the stock foam/cover, and having a choice of thickness really made the difference in my case.