The 305 is the most common and medium sized variant of the Base-X series. It has a multi-use role whether to house personnel, serve as a medical facility, or used as a dining area, it is large enough to fulfil most roles. It is large enough to house about a dozen personnel and features 6 doors, 6 windows, and 2 ridge vents for air circulation. A secondary layer of a white interior canvas skin called a liner is optional. Its purpose is to provide additional insulation and includes electrical, an ECU plenum for air distribution, and a soft green floor for weather proofing which comes as one piece and can be installed on the interior of the frame. The frame consists of durable aluminum poles which the exterior canvas skin is connected to, and the system can be setup in a matter of minutes by a trained crew.