Application2006-13 compatible for BMW 3 Series E90 E91 Rwd only Note: Not suitable for X-drive or M3 modelsSpecificationsQuantity: 2 piece front + 2 pieces rear Spring rate Front:10 kg/mm (560 lbs/in) Spring rate Rear:8 kg/mm (448 lbs/in) Damper: Non adjustable Damper Adjustable height: Yes Adjustable camber plate: No Warranty: one year warranty for any manufacturing defectFeature- Able to lower ride height by 1\'\'-3\'\'; allows user to have a more aggressive stance.- The user can enjoy a comfortable riding experience in all road conditions.- Pillow ball top mount -- this design helps combat noise while tuning. It also improves the steering feel and response- Twin-Tube Shock design is used for low internal frictional resistance in order to increase efficiency and keep shock temps low.- Height adjustment does not sacrifice damper stroke length.- These coilovers are able to have their height adjusted without being taken out of the car.- High Tensile strength performance spring---Tested under a 600,000 time continuous compression test, the spring distortion was less than 0.04%. Plus, the special surface treatment improves the durability and performance.- Adjustment tools included in the kit.NoticeNo instruction included; Professional installation alignment suggested. Please check our store for other auto parts you may be interested in. Please feel free to contact us for whatever we can help.