We offer a range of MCUs that will not only house the normal contactors and current measurement shunts but, depending on the requirement, SGC, TSLM, and PDC units, as well as Lithium batteries (usually two ETX900-24's). They will connect aircraft electrical bus(es), onboard batteries, external power (GPU), and engine-driven generator(s) in various arrangements, including ones with parallel-series starter boosting. Our MCUs are not only more compact compared to alternatives, but they weigh significantly less. It, we believe, allows for more mounting options and versatility. We have found that our MCUs make wires significantly shorter between batteries and starter, which effectively increases starting power. With batteries inside, they give added protection to the always live wires that now run internally. Our MCUs also allow for charging batteries via the GPU plug.