TPO 0.75x Focal Reducer for Ritchey-Chretien Telescopes | OPT Telescopes
SVBONY 2 Inch 0.8x Focal Reducer / Flattener for SV503 102F7 f/7 Refractor | eBay
Explore Scientific 3" Field Flattener .7x Focal Reducer - FFFR507X-00
Agena's Guide to Focal Reducers
Vixen - Focal Reducer for AX103S | Telescopes
Amazon.com : Astromania 0.5X Reducer for Photography and Observing - 1.25" Filter Thread (28.5x0.75MM) on Both Sides - Reduces The Focal Length for Visual and Photographic Use : Electronics
Laowa 0.7x Focal Reducer for the 24mm f/14 2X Macro Probe lens - Newsshooter
Focal Reducers - Complete Overview and Function - YouTube