For the following the Collar will be required for the crankshaft:

• Early R32 RB26DETT engines
• RB20DE
• RB20DET
• RB25DE
• RB25DET
• RB30E
• RB30ET

Our Collar is a premium product designed to fit perfectly with a tolerance fit.  It is secured with grub screws which will not come loose, providing loctite is used.  If you've seen problems with poorly constructed or fitted N1 Collars before, then you'll understand why this one is perfect. 

Unlike any of the other Collars we've seen, ours includes simple step by step instructions (in English).