This genuine Squarehood is a bayonet mount hood that fits on both the Fujifilm XF 33mm f1.4 R LM WR
23mm f1.4 R LM WR, (Fujis newer versions of these focal lengths).
It will also fit the 16-50mm
The hoods are anodised aluminium and come with a rubber / plastic cap which firmly clicks into place. They fit over a 58mm filter.

The hood is 23.60mm in length but only adds 11.5mm to the length of the lens.

No adjustment of these hoods are needed, they simply twist and click onto the lens.