A P4 Unit (Pressurized Portable Potato Patch) is a SSCC-Medium container with a tiny aether generator and an environmental system stored inside. It is used to raise potatoes in a starship's cargo bay to supplement on-board food supplies, either because of shortages or just to ease pressure on Star Army Logistics. The P4 Unit can be used to raise other types of food and plants as well, but potatoes are the default, first, and most common product for the container, hence the name.

P4 Units contain artificial gravity, racks of soil-filled troughs, air and water tanks, and recycling systems. A starship's cargo specialist needs only to inspect the unit about once a week and (with the cook's help) harvest the potatoes when they are ready. P4 units can also be deployed on planetary surfaces if desired.

Civilians can also purchase P4 units from Ketsurui Zaibatsu for a cost of 2000 KS.