The Lightsphere® diffusers are designed for use with normal hot-shoe mounted TTL flash systems. With that in mind, our diffusers are compatible with hundreds of flash units and are designed to give a custom fit. It is easy to size-down to a flash, but the maximum flash dimension is approximately 3 1/4” X 2 1/4”. For this reason, many older, handle mounted flash units, like a Metz CT-45, are not compatible.
If you still are uncertain of your flash, please contact our customer support line at 800-906-6447.