50 square foot unit, good for storing a room worth of furniture, like a bedroom or college dorm.
100 square foot unit, good for storing a large room worth of furniture, like a living room or several smaller rooms. These units are extra tall.
150 square foot unit, good for a very small house or apartment worth of furniture or 3+ bedrooms.
200 square foot unit, good for a small house worth of furniture. These units have their doors (8 ft) along their long side (20ft) therefore they are not appropriate for the storage of vehicles or trailers.
300 square foot unit, good for a medium size house of furniture or the storage of a vehicle.