The Danube-class was first commissioned by Starfleet in 2368 for use as a light multipurpose craft in situations that demanded a vessel more capable than a standard shuttlecraft, but lower profile than a full-sized starship. With this flexibility, a runabout could be utilized as a long-range personnel and cargo transport, an agile mobile defense platform, or a high-speed reconnaissance vehicle.
Specifications from ST-Intelligence.
Description from Memory Alpha.
Modifications by Edwards.