SENSEN 1600-FS Front Pair of Struts for 01-06 Kia Optima Precision designed for a direct fit and restore factory ride height. Nitrogen Gas charged, Twin-tube design Precision robotic welding for consistent, accurate quality and dependability Quality Control system certified by ISO9001:2000 and ISO/TS 16949:2434 SENSEN limited lifetime warranty, Purchase with confidence.