Note: Due to the nature of 3D printed materials, it is not recommended to leave the diffusers in a hot car or direct sunlight for extended periods of time otherwise they may deform.
Designed specifically for use with the Yongnuo YN24 twin flash and the MP-E65 lens. They can be used with other lenses but because of their size they are less effective when used with lenses with a longer focal length, or when the subject is much further away.
There is also a version for the Canon MT-24EX.
Light is reduced by only just over 1 stop when using these diffusers, so if you already use some sort of diffusion and then use these, you may find that your images are too bright or create hotspots again. You will need to reduce your flash level or change other settings to remedy this but anything you change will be for the better because you have more light :)
Macro Diffusion Kit Review by The Art of Stuart Wood
These attach to the metal rings supplied with the flash (pic2). Once attached and the metal ring is tightened onto your lens, the ring mount (pic 3) should click into place and not be able to spin (pic 4).