This is a custom made 68 tooth 50mm cog crank pulley with an Innovators West balancer inside. I sent the cog pulley to IW and they machined out the center and mounted their balancer in the center, then added the MSD trigger wheel and a single "V" belt pulley, which can be easily switched out for a dual. Over $700.00 in this set-up. $375.00 shipped USPS Parcel post. If interested, PM or e-mail me at roadwarriorsvt@earthlink.net