Grosse user, I use one to two pairs per year because the silicone sheds are damaged over time; I tested other references, but these are the ones I found most comfortable (this size "standard" size was sold as a child there a few years) but also as the most loyal in terms of sound and everything use with their average attenuation, and with such quality / price ratio. There are certainly better, but really much more expensive.
These caps are made to hear they a substitute for a noise-canceling headphones on a construction site as I have read in other reviews !!! We must also choose its size and take the time to place them, otherwise they are useless.
Note that the rigid rod can not use them to sleep.