This module is a variation on the 1973 Classic Serge Peak and Trough module. It is much like the Analog Logic Peak and Trough, though a little less precise. It is presented here for those who want to build themselves a classic Serge. Both the Peak and Trough operate in the range of 0V to half of the positive power rail, i.e. 6V on a 12 volt system, though in practice, you may find the Trough section does respond to input voltages going a volt or two below 0V.
The Peak section is effectively a diode OR gate. While the Trough section is the reverse of the Peak, based around a diode AND gate.

http://www.elby-designs.com/contents/en-us/p947_ES84_-_Peak___Trough_Detector.html

• ? mA +12V
• ? mA -12V
• ? mA 5V

Available as an assembled Module and as a DIY project.

No info about availability.