This Module is currently available.
Attack-Decay envelope generator
EG is a 6HP voltage controlled Attack-Decay envelope generator with an End Of Cycle (EOC) trigger output. The button (re-trig) toggles between one-shot and re-triggerable modes, and the CV input (with associated attenuverter) modulates the overall length of the envelope. Loopable, chainable, fast-as-you-need-it. EG is a staple.
These merchants probably sell this module. Huh?
Super Synthesis EG