Arnott's new air spring for the rear of the 2011-2017 BMW 5 Series Wagon/Touring (F11) and Gran Turismo Crossover (F07) features a Conti air spring bladder, heavy-duty crimping rings and high-impact plastic resin top and bottom pistons. Arnott's rear air spring fits either the left or right side. The air spring is designed, assembled and tested in the USA. Arnott backs this air spring with a Limited Lifetime Warranty and recommends replacing both rear air springs at the same time.