A linear guide, which has a guide carriage that is mounted in a longitudinally moveable manner on a guide rail and to which an additional component, for example a measuring head, can be fastened by a fastening device. The fastening device has a pin which is fastened to the guide carriage at the end side. The pin has a fastening section to which the additional component can be fastened, that projects from the guiding carriage at the end side.