An analog Ring Modulator is in mint condition. One owner never giggled. 

Designed by Bob Moog himself. It works by multiplying a mono audio input with a carrier oscillator to produce the wild, famous and vintage ring modulator sound. The MF-102 is a Stomp-Box style Ring Mod with knobs to control LFO amount, LFO rate, Modulator frequency and Modulator Mix. The LFO can be switched between sine or square waveforms (0.1Hz to 25Hz). The carrier signal can be switched between low or high modes (2Hz to 4kHz).

Basically you can feed any mono sound into the MF-102: synth, sampler, DAT, record or microphone. The Carrier signal creates a frequency that will be multiplied to the input sound. This carrier signal is variable via the Modulator frequency knob, hi/low switch and Mix knob. The input sound can be levelled or overdriven using the Drive knob. The LFO is used to modulate the Carrier + Input sound for adding motion and sweeping effects to the cool ring mod effect. The MF-102 is classically endowed with CV (Control Voltage) control with which you can use to basically add a Moog ring mod to your existing analog CV/Gate synths. The MF-102 also has four expression pedal inputs for remote control of the knob parameters. A great analog effect from the Man himself.