This is legally a pistol because it has a pistol stabilizing brace rather than a stock. The stabilizing brace has hole in it meant to wrap around your forearm and is legally "not meant to be shoulder" (but you can shoulder it) So this is pistol and not SBR. I hope this helps!

Herman, it has a Stabilizing Brace" and not s Shoulder Stock so the classification remains as a standard Pistol/Handgun. -- https://vpc.org/wp-content/uploads/2019/08/Pistol-brace-ATF-letter-March-21-2017.pdf

Herman, this has a pistol stabilizing brace, not a stock. Therefore it is not meant to be fired from the shoulder, so it is not a rifle.