The OggLab Domes are produced in three different sizes to cover almost all of the subjects normally shot in macro photography. To adapt to different situations they can be easily used with one or two walls. The double wall solution allows the best diffusion of the light source which is useful for highly reflective subjects. The single wall can be used with relatively low reflective subjects to take advantage of the maximum brightness. An easily removable black sector allows for shading on one side. Find a full review on Enrico Boninos website here: https://enrico-bonino.eu/diffuser-dome/The domes are produced with FDM technology which offers the advantage of thin walls (0,6 mm) to minimize the loss due to the thickness of the material, and knurled to obtain a better diffusion of light.Transparency: 1 wall 70%, 2 walls 55%The base has four 1/4" threads in the event that you want to use it in a non-vertical setup using articulated arms. Sizes (inner diameter): Small: 92 mm Medium: 116 mm Big: 139 mm Download Technical Sheet