Coilover compatible for Bmw E30 Series 3 Adjustable Suspension Coilovers Lowering Kit 51mmApplication Notice: No Top Mount IncludedModification Required If You Use OE Top Mount Struts come in two sizes: 45mm and 51mm. The bigger size on Tourings and Cabriolets. If you are unsure of what size strut your car has, and you can't remember your maths lessons, then use a bit of string. Wrap the string around the strut, and then measure its length; 141mm means a 45mm strut, and 160mm means a 51mm strut. Does NOT fit the M3, iX (All Wheel Drive)