This adapter is designed exclusively for the GRIIIx. The adapter is attached to the mount by removing the ring cap attached to the GRIIIx body. I bought it thinking I might use it, but in the end I only attached it for a test and did not operate it.
RICOH GR IIIx HDF, Expansion model of the existing GR series with a built-in Highlight Diffusion Filter, Digital Compact Camera with 24MP APS-C Size CMOS Sensor, 40mmF2.8 GR Lens (in the 35mm format)
Ricoh GR IIIx Digital Camera [Focal length 40mm] [Equipped with24.2M APS-C size large CMOS sensor ] [The ultimate snapshot camera] [Approximately 0.8 seconds high-speed startup] [High speed hybrid AF]
RICOH GR IIIx with accessories, VGC
S/C 1421 RICOH GR IIIx III X Compact Digital Camera w/ Box From Japan Top MINT
Ricoh GR IIIx HDF Compact Digital Camera Black 24MP f/2.8
RICOH GR IV HDF, Expansion Model of GR IV with a Built-In Highlight Diffusion Filter. Ultimate Premium Digital Compact Camera with NEW 25.74MP APS-C Size CMOS Sensor and NEW 28mm f2.8 GR Lens