Transgo Shift Kit Mercedes Chrysler dodge Jeep Sprinter NAG1. its 1996 and up equipped Chrysler, Dodge, Jeep and Mercedes vehicles. "Chrysler calls this unit a NAG1" Includes Pressure Regulator valve and Lube Regulator valve assembly Convenient drop in, No special tooling or machining necessary! Addresses Insufficient Pressure Rise, 2-3 Flare, TCC slip or Shudder, Soft Shifts, Shudder on Hard Throttle Acceleration from a stop. Improves and restores correct drivability with added durability. Notice: There are (2) sizes of Pressure Regulator valves. Our kit contains the small Pressure Regulator valve version which is the most common. The larger PR valve comes in V8 engine sizes which are usually High performance or turbocharged High output vehicles.