The ‘Custom’ mode gives you complete control on what frequency, intensity and duration you can use! You can select any frequency within the range of 0-100 Hz, any intensity within the range of 1-100 gauss on the controller or 1-50 gauss on the mats and adjust the time from 5 minutes to 12 hours.
This mode was only added for those users who want to be very specific with what frequency they want to use and puts you in control. Maybe the user has seen a specific study that was conducted and wants to replicate that study. However, I still believe that the body deserves more than one frequency and to avoid the possibility of your body being accustomed to the same frequency session every time, I recommend that almost every user sticks to the pre-set modes for all desired outcomes.