Do these reduce the volume as a pair of earplugs should? yes, they do. They also sound very transparent and I can clearly hear how things sound while using them, nothing sticks out as skewed or wrong.
But... The lever for adjusting the volume is very loose and sloppy. I think that at this price point, they should at least have a nice feeling lever with some resistance that makes it stay where you want it. Perhaps it should even be stepped, as it's quite hard to match the setting for both ears. For comparison, I bought a pair of KNOPS way back through Kickstarter, which are way worse as an earplug for music goes, but has much a much nicer interface for adjusting volume that feels and looks premium.
The glue on my left earplug also failed, and it fell apart. From this, I know that the insides are nothing but a cheap feeling plastic housing with a plastic disk in the middle. The glue holding the magnets in also failed on one side as I pulled them apart one day. They are back in working order now thanks to good old super glue.
In summary, I feel this is a cheaply made item sold at a premium price. Functionally, they do the job. I'll even say that they are the best-sounding/most transparent earplugs I have ever used, but, the fit and finish leave a lot to be desired.
