Envelope and LFO
The ADSR module offers the classic four-stage envelope (Attack, Decay, Sustain, Release) which accepts CV control over each of the stages. For the time values (A, D, R) the value set by the knob can be increased to five times the duration by the corresponding CV value. For the Sustain value the knob and CV value are simply added.
The envelope is also loop-able by patching the end output into the gate input, becoming a very adjustable LFO.
These merchants probably sell this module. Huh?
Tangible Waves ADSR
Tangible Waves Tangible AE Modular ADSR