This is a commercial version of RF-17-1.
The mechanism is the same asRF-17-1. The traditional sheath under a real rice ball is "bamboo sheath" Inboth of the works RF-17-1 and RR-17-2, the "bamboo sheath" is made of thesame wood. In the RF-17-1, it is very thin just like a real one. On theother hand, in the RF-17-2, the thickness of it is around two millimeters.It is stronger than the thin one. The size of the setting are a little different between RF-17-1 and RF-17-2.