Yes, this is the first model Trooper, so it's just called Trooper. They chambered it in .357 later on, and if my memory serves me right they renamed it "Trooper 357" and later on just "357". It's an E-frame gun (or it might have been called "medium frame" back then), same action that was later used in the Python. The only technical difference between the Python and the Trooper is that the Trooper has the firing pin on the hammer, whereas the firing pin in the Python (and the 357) is in the frame.