Choice of (changeable) filters. Flat attenuation. Low profile earplug, not very visible.
Listening to music should be enjoyable and not pose a risk to your hearing. Excessive loud music may lead to irreparable damage to your ears. Pluggerz Custom-Made ER have a flat filter, that does not distort sound and therefore guarantees optimum music quality.
The filters from the ER are changeable to but tend do damage more easily than the Music 2-in-1. The advantage from the ER over the Music 2-in-1 is the fact that they are less visible in your ear.
The hearing protectors can only work if they are fitted into the ear correctly. Read here how you should do this.