The technical facts of the SteelSeries Siberia In-Ear Headset are as follows:

Frequency: 28 – 24.000 Hz

Impedance: 16 Ohm

SPL @ 1kHz: 90dB

Cable length: 1.0m

Jack: 3.5mm

The microphone to be quite honest though is more of a bonus than anything else in my opinion as the headphones are truly incredible.  I also wanted to run them through more rigid testing so I decided to take them with me to the gym.  I used the supplied extra pair of ear sleeves which allowed to go deeper into my ears.  This kept them in my ears while jogging and throughout the entire workout.  They also did a great job of blocking out surrounding noise.  I could hear nothing while using these headphones, not any background noise at all.  It was truly incredible to say the least since a gym is a loud place with a radio playing, people dropping weights, chatting, etc.  If you want to block out noise and just tune into your music then this is the headset for you!

As you can tell I was extremely impressed with the SteelSeries Siberia in-ear headset.  The package included here is worth a lot more than what they are charging for it as the audio quality is incredible for gaming, music, etc.  The extra carrying case, ear pieces, extension cable, and supplied separate microphone only add to the package further.  If you are looking for an amazing pair of headphones, this is the best audio value around hands down.  Highly recommended!