Lowering spring, sportspring Z4 ROADSTER 18i/20 mm. Made in highquality silicone steel with High quality Epoxi coating to stand salt and other woundsi/23i/28i/30 mm. Made in highquality silicone steel with High quality Epoxi coating to stand salt and other woundsi lowers 30 mm. Made in highquality silicone steel with High quality Epoxi coating to stand salt and other wounds