The Etymotic Tuning Kit was derived from the desire for Etymotic users to modify the sound of their earphones. To each of us, the sound we hear from any hearing device sounds different as we all have different frequencies curves to our natural hearing based on age, ear shape, previous hearing damage, etc. What Etymotic is offering is the listener the ability to tune their Etymotic ER series earphones to their own tastes and hearing profile. By incorporating 5 different filters of varying resistance you can go from a more detailed sound using the white filters all the way to a warmer and darker sound if you go with the orange filters. The full specs of the included dampers are below. White – 680 Ohms Brown – 1000 Ohms Green – 1500 Ohms Red – 2200 ohms Orange – 3300 Ohms