This is the Behringer SYSTEM 100 140 DUAL ENVELOPE/LFO. An authentic reproduction of the original ÒSystem 100MÓ circuitry from the 80Õs that can fit in a standard Eurorack case. The best part? ItÕs at a very affordable price. Mix the 140 DUAL ENVELOPE/LFO in with your existing rig or start your modular synth journey from here. Either way youÕre sure to have a lot of fun.