FlashKap - Evolved Ring Flash Diffusion – Flashkap
Bolt TTL Macro Ring Flash with Transceiver Set for Canon
Amazon.com : Godox RFT-25S Reflector Diffuser Dish Beauty Dish with Silver Interior for Godox R200 Macro Ring Flash Speedlight Speedlite Head for Photography : Electronics
Paul C. Buff, Inc. | AlienBees™ Ringflash Front Cover
Cheap but efficient handmade macro ring flash diffuser: Macro and Still Life Photography Forum: Digital Photography Review