The nose pads are always fitting to the skin and are consumables.
There are various nose pads, but this is a hard type nose pad.
When you sweat or take a water in your body, the hard type will be a little slippery, and the sunglasses will not feel like wearing them.
However, the silicone pads stick to your skin will be loose and difficult to remake makeup, but the hard pad can be flipped on the reverse side, so it is difficult to stick on makeup.
In addition, the silicone pad has less constricting feeling on the nose. (Conversely, it is also easy to slip...)
Installation is limited to a screwdriver-type pad carrier. Perhaps if your existing glasses or sunglasses are a "screw-on pad", you can install them by yourself, but if you have a one-touch or tight-fitting pad, you cannot install them before making your purchase.