Designed as a replacement insert for your Bolt Drive or Spline Drive Sprockets. HAT WASHER SPECS - Convert your 22mm center bore to 19mm - High quality hardened Steel that resist indentations from splines. - Universal for any 22mm center bore sprockets - 3 versions made for 4.5mm, 1/4", and 5/16"(8mm) sprockets SPLINE DRIVE INSERT SPECS - Heat treated high quality steel - 4 versions made for Original Spline Drive, Lite 19mm Spline Drive, Lite 22mm Spline Drive, and Older "9 Bump" Lite Spline Drive Sprockets
