Whereas conventional shipping containers have metal walls that are corrugated for strength, the 20-ft (6-m) Unit One features flat, smooth, insulated walls made of a high-strength yet lightweight fiberglass/resin composite. Because the Unit One is so light, it's reportedly able to carry 11% more dry cargo than a regular container (without exceeding total weight limits), and 17% more liquid than a traditional container equipped with a Flexitank bladder – and unlike some shipping containers, it does so without bulging.

The insulation, meanwhile, helps keep the inside of the Unit One from getting too hot when sitting out in the sun during the day, and from getting too cold when the temperature drops at night. As a result, the container's cooling and heating systems don't need to run as often, plus there's less chance of cargo-damaging condensation forming inside.