This product is the best in the business for absorbing engine vibrations. For any customers looking to use a K20 oil pump conversion or track their car you should consider this to be on the list of items to get. Instead of rubber-style stock pulleys and competitor options, this harmonic balancer pulley is designed with thick silicone fluid that absorb vibrations of any HP and RPM range with no service/maintenance requirements! Please note this harmonic balancer now features a bolt pattern on front to allow for aftermarket drive pulleys to be bolted to it.  You can drive your oil pumps and other products off this pulley! Features: All horsepower ranges No service/maintenance required Filled with dense liquid