ADSR Envelope Generator
The EMW ADSR 101 Envelope Generator was designed to have a ultra fast GATE response in order to produce very sharp attack times. This module only uses 6 HP space and consumes little current from the power supply. Its simple and reliable design makes it a good additional ADSR source that fits perfectly in any Eurorack system.
http://www.electronicmusicworks.com/eurorack/adsr-101.html
No info about availability.
$76