Up for sale is JT 2006-2011 EX650 Ninja 650R Kawasaki REAR SPROCKET STEEL 45T-520 KAW JTR478.45. The vendor part number is JTR478.45. Please read the title to know what is for sale. Catalog Description� TOP QUALITY AT ECONOMICAL PRICES Made exclusively from the finest Japanese 545C high carbon steel Heat treated and hand finished to meet or exceed O.E.M. standards Outlasts any mild steel or surface hardened sprocket as much as two or three times over .