In the Tekonsha Prodigy line I believe there was the Original Prodigy then the Prodigy P2 and most recently the Prodigy P3.
I believe the original Prodigy is often called a P1 where Tekonsha never used that term.
Most important the Prodigy controllers have a Limited lifetime warranty.
I had a P3 replaced even though I could not find my original sales receipt.
This description of differences between the Prodigy controllers I got from a Tekonsha web site.
"There are 3 big differences between the Prodigy, # 90185, and the Prodigy P2, # 90885, brake controllers. The most notable difference is the LED display is blue on the P2 where as it is red on the Prodigy. The second difference is that the P2 can be mounted at any angle, a full 360 degrees, where as the Prodigy needs to be between level and 70 degrees nose up. The third big difference is that the P2 can be used with electric over hydraulic systems. A couple minor changes include some inherited software and technology from the Tekonsha P3, their top-of-the-line controller. The P2 also offers reverse battery protection."