In Stock. The Fernandes Sustainer Kit is finally here!! Fernandes Sustainer is an electromagnetic system powered by a nine-volt battery, and works in conjunction with bridge pick-up and the sustainer circuit board. It magnetically vibrates the strings once you start playing and it gives you endless sustain. In the second mode it give you harmonic feedback to create 5th harmonic feedback at any volume level. The kit is avaliable for any solid body guitar.