Unknown Accessory

[Anthsmith]

Does anyone have any idea as to what this accessory is, the small inner thread diameter is 37.5mm and the larger top inner thread is 55mm Thanks

 

[johnf04]

Some sort of filter adapter ring?

 

[shimokita]

The Fuji x100t has a "similar" accessory as the lens has a male thread and you need the accessory to be able to use filters in the "correct" orientation. However the Fuji accessory is 49 mm treaded on both sides...

Is the accessory heavy or light thin aluminum? Any context?

 

[Anthsmith]

Hi thanks for your input the ring is light Aluminium, and must be more than 10 yrs old.