Keystone RV Co. has redesigned its year-old Zeppelin series of ultralight travel trailers with more functional floorplans, according to the company. Also new for 2005 are exterior colors and light-cherry interior accents designed to give the coach a richer feel. With seven floorplans in lengths of 19 to 30 feet, Zeppelins weigh 3,000 to 4,800 pounds. The aluminum-and-laminated fiberglass Zeppelin has a starting price of $15,800.