A Diamondistributor with 4 (2^2) inputs and outputs, in 1 (2^0) layer. Recommended to use inputs and outputs in order by distance of their ends from a perpendicular bisector. That is, if they are facing north, then use the northmost OR southmost belts first. Place two of this next to each other for (part of) a T3L0, or stack two of this for (part of) a T3L1.