Words from the Jetter Website:
The Helium is turning into many players' secret weapon. This low-gain design has that elusive quality of making almost any gear sound better... so much so that many are leaving it on all the time just to sweeten things up.
Harmonically rich and smooth as silk, the Helium has just the right amount gain on tap to cover the bases from edge-of-breakup to driving rhythm. The Helium is also a dream to stack with other pedals opening up a whole range of tones that simply aren't available with most single pedals.
The Helium, placed after other overdrive pedals, offers the most flexible and satisfying tones we have ever heard. It might seem counter-intuitive to place a low gain pedal after a higher gain pedal in the chain (and we generally follow that rule) but the Helium reacts like no other pedal in our experience.