“Darned fine looking gun. Might take a closer look.”
I believe that the one in the picture is the SU16A. The stock and trigger can be folded by removing a pin - the gun cannot be fired when folded.
The “C” version (SU16C) has a folding stock which neatly swings over the mag making the gun very small but still usable. The trigger section can also fold at a second location by removing a pin but then the gun cannot be fired. The C’s threaded barrel lets you use a muzzle brake which really works well to counteract the recoil resulting from the low gun weight.