Diffuser for the built-in flash, attachable by Sony E-mount to the front of a reverse mounted Lens. Allows for better lighting in macro/close-up photography without the need of an additional external flash.
Rotates independently of the mount, to better align with the flash. Can also be bent outward with a bit of heat, to increase lighting.
Developed for the Sony A6400 in conjunction with this reverse mount.
It can additionally be used for portrait photography by attaching at the end of a normally mounted lens with a reverse mount adapter. This reduces flash intensity, and gives it a much softer light.