Amazon.com : NEEWER EF-EOS M Lens Mount Adapter 0.71x Autofocus Speed Booster Compatible with Canon EF Lens to EOS M Series Camera EOS M M2 M3 M5 M6 M10 M50 M100 M200
Amazon.com : Canon EF to Sony E-Mount Speed Booster, VILTROX EF-EII 0.71x Lens Mount Adapter for Sony e Mount Camera zv1 a6000 a6400 a6500 : Electronics
Canon EF Lens to RF-Mount T CINE Speed Booster Ultra 0.71x Adapter, Black - Walmart.com
Amazon.com : VILTROX EF-E II 0.71x Auto Focus Reducer Speed Booster Adapter for Canon EF to Sony E-Mount Camera a9 a7r iii a7r ii a7iii a7s a6500 a6300 : Electronics
VILTROX EF-M2 II Focal Reducer Speed Booster Adapterfor Canon EF Mount
Viltrox EF-EOS M2 EF-M Lens Adapter 0.71x Speed Booster for Canon EF lens to EOS | eBay
Canon EF-EOS R 0.71x Mount Adapter for EF-Mount to EOS C70 4757C001