This is a nice bag but it is more cosmetic than protective. This is clearly designed to work with a number of different THR models. I am using it for the THR-30 II, it just about fits.
I don't think this bag will offer any protection. I also don't feel confident that I can put the amp in it and carry across my shoulder without the strap breaking at some point. This bag is best described as a nice way of storing your amp when not in use, it is a good dust cover and way of storing picks, leads, power supply, capo. It is not very generous space wise for the THR30. The fact that the handle sticks out of the top is understandable but I would have preferred something that was at least shower proof say if you were taking it out of the car when it is raining. There are better options out there but if you are like me and want all the official accessories is nice but not effective.