The VSD1S since its inception has been an extremely popular budget option for many audiophiles. Vsonic had build on what made the VSD1 so popular by creating the VSD2S. The VSD2S features an all new shell design and improved clarity as compared to the VSD1. Difference between VSD2 and VSD2S: The VSD2 features a slightly stronger bass while the VSD2S edges slightly ahead with slightly better clarity and treble. Accessories: 3 pairs of silicon tips (S, M, L) 1 pair of biflange tips 1 shirt clip 1 pair of ear guides 1 pouch Specification: Driver unit: 10.7 mm CCAW efficient moving coil drive unit Rated Impedance: 16 Ohm Sensitivity: >104 dB/mW Frequency response: 5 Hz- 24 KHz Plug: 3.5mm jack Cable: 1.20 mm