Great module designed by Rick from Frequency Central (FC:UK) - you might ordinarily know him for his seriously stunning boutique guitar pedals and amps but recently he's been branching out into euro modular.
This design is based on Electric Druid's VCADSR and Rick offers it either as a built module or you can buy the PCB set (and programmed IC) for a very reasonable price. Rick also sells a faceplate for it but, typically, I decided to make my own from acrylic.
This is a seriously underrated envelope module. There's not many decent VC-controlled ADSRs in euro modular, certainly ones that have CV control over each stage. The Recycler goes one (several) stages further and has a couple of looping modes, which the cycle speed goes well into audio territory. This means you can use it as a wave-shaped VCO amongst other things. Great module, here's a demo I did modulating the envelope stages and feeding the outputs into a VCF and pitch control of a VCO.
electronics DIY modular recycler