Fleece Performance 03-18 Cummins Coolant Bypass Service KitComplete kit to service your Fleece Performance Coolant Bypass Includes all O rings, fasteners, and a new thermostat. Two thermostats included to service all production years, you will only use one (1) of the included thermostats when replacing your bypass thermostat. This kit does not include the Cummins thermostat. The kit includes 3 new square cut O rings and 1 new standard O ring as well as 2 new O rings for each of AN fittings. When used with