Fredenstein Artistic Leveler, optical Compressor in the 500-series with "Multi Channel Link" function. It has external sidechain input via AUX-Input when using an Bento 6 or 10 500-frame. The OPA2 discrete audio operational amplifier (changeable), reverce Mancini circuit, rotary knob for input gain ratio, release, output gain and wet/dry mix- function. Attack is adjustable (12, 25 and 50 Milliseconds), and adjustable ratio from 1,5:1 to 7,5:1. Switchable side-chain filter 150 or 300Hz, and 16 digit LED Display for gain reduction metering. Clip-LED, bypass-switch, link-function for second Artistic Leveler. Works with compatible 500-series frames.