The EH-5000 is a ring modulator with blend, fine, and shift controls. - Model Name: EH-5000 - Type: Ring Modulator - Function: Frequency Analyzer - Controls: Blend, Fine, Shift - Connections: Effect Out, Direct Out, Input, Filter Out A ring modulator often used by Jeff Beck. I was thrilled when I bought it. That sound comes from the combination with a tremolo arm. Thank you for looking.