What is the difference between the Bell 412 and the Bell CH-146 Griffon?
Fundamentally, the CH-146 is a Bell 412EP, which you can still buy from Bell today.

Some features on the CH-146 you won't find on civilian counterparts:


Weapons.  The CH-146 has attachment points for weapon mounts that aren't typically found on the Bell 412.
Wescam T-16D-A Thermal Imaging System. This wasn't a production addition to the CH-146, but it appears be common on these helicopters.  Similar aftermarket systems might be in use on Bell 412s in police use.
Wire Strike Protection System - some civilian helicopters do have this, but they're particularly common on the CH-146 and other military helicopters.
A Canadian Forces paint job.