Fitment Type: Direct Replacement Manufactured from High-grade Materials for Long Lasting Durability Made of high quality material for durability and stability Pressure can be adjusted by springs or air (nitrogen); Operation of the coil-over springs and air cylinder is helpful to reduce the shock No instruction included, professional installation recommended Product Description Made of High Quality Materials, Stable Characteristics, High Reliability. Specification: Condition: 100% Brand New Material: High Quality Aluminum Alloy & Steel Position On Bike: Rear Eye to Eye: 320mm (12.59 Inch) Eye Diameter (for mounting bolt):12.5mm Spring Thickness: 7.5mm Spring Width: 63mm Total Overall Length (uncompressed): 360mm (14.17 Inch) Package included: Shock Absorber And Necessary Mounting Hardware Note: This product is measured by hand and may have an error of 1-3cm, which is based on the actual product. Due to the screen and lighting configuration, the colors may be slightly darker or lighter