The DIY version of the Omiindustriies 4013 Eurorack module. It's Dual Digital Data Storage in eurorack format!
A little info on the 4013 series digital logic IC:
"The 4013 device consists of two identical, independent data-type flip-flops. Each flip-flop has independent data, set, reset, and clock inputs and Q and Q outputs. These devices can be used for shift register applications, and, by connecting Q output to the data input, for counter and toggle applications. The logic level present at the D input is transferred to the Q output during the positive-going transition of the clock pulse. Setting or resetting is independent of the clock and is accomplished by a high level on the set or reset line, respectively"