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 Canon MT-24EX 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 Yongnuo YN24.
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 :)