Based on the Roland System 100m envelope generator

The System X ADSR is your basic envelope generator with a few twists; envelope speed can be selected with a Fast / Slow toggle switch, output is available in both standard and inverted signals and most of all – THIS THING IS FAST!

No matter what type of envelope generator you’re using now your modular isn’t complete without at least one of these little gems!

The System X ADSR comes in a 1U width form factor with 25mm knobs controlling 4 potentiometers

https://richsstudioproject.wpcomstaging.com/product/frequency-central-system-x-adsr-envelope-generator/