Mustang's 15" wide sport touring solo is less rounded on the sides for a sportier look and is available with or without a fully adjustable and easily removable driver backrest. Recessed Passenger seats are designed for use with the built-in driver backrest. for seats without a built-in driver backrest, the passenger seat extends forward for increased driver back support. Be sure to add the matching sissy bar pad (#79082) with built-in extension for maximum passenger comfort.