Custom Earplugs with acoustically tuned filters were developed so that you can be in loud environments yet still listen at a safer, more comfortable level. The changeable filters lower the sound levels equally across all frequencies — a sonic equivalent of turning down the total volume level. And since Custom Earplugs reduce all of the frequencies evenly, they avoid the skewed, muffled sound effects common to over the counter earplugs.
With these headphones you can't hear anything when you're on the street running, not a car horn, not a siren, nothing. And pretty comfortable given that they're in-ear.
FOR THE ABSOLUTE BEST IN FIT & SOUND, GET THE FULL ROCK STAR EXPERIENCE WITH A SET OF PROFESSIONAL CUSTOM MOLDED MONITORS. THIS IS TOP OF THE LINE CUSTOM IN EAR MONITOR.