I love these IEMs. They sound great and the fit is very customizable. This is what I use as my back up to my custom molded in-ears.

• Dual high-performance dynamic drivers deliver incredible lows with precise mids and highs
• Shielded, Braided Cable is designed for extra durability and sonic performance
• Detachable MMCX connector that swivels for increased comfort and durability

The MP-220 steps up the count with two dynamic drivers in each monitor. In addition to offering cleaner performance at higher levels, it allows the monitor to achieve higher efficiency evenly across the entire frequency range. Because you have twice the drivers taking care of the same job, they can resolve details and nuance in the sound much better, this also means increased bass which dynamic drivers are particularly good at.