1. The aluminum alloy chamber that is cut by a diamond blade in a single machine process provides a more powerful bass and clear sound. However, the PTE front shell will make the earphone more comfortable to the skin. 2. Ergonomic design of the cable shell: when wearing, it fits closely to the inside surface of human tragus and goes along the incisura intertragica, so that the earphone won’t slip out during exercise. 3. The soft silica gel cable shell offers more comfort to the skin. 4. The earpiece design has only two parts. The front part contains the speaker and is rounded for more comfort and for a more secure fit in the ear. The back part is for the fingers to hold. All in all, it is very minimalist.