DK-4 Rinnai Kanta-kun Optional Part Small Item Drying Shelf

Purchased this month, but it was not compatible with my device, so I couldn't use it. The instruction manual and outer box are not included. It has been opened but is unused.

Rinnai Kanta-kun Optional Part
DK-4

Compatible Models: RDT-80 Series, RDT-54S Series