Breakthrough announces first third-party EF to RF Drop-In Filter Adapter: Digital Photography Review
Amazon.com : Meike MK-EFTR-C VND Drop-in Filter Auto-Focus Mount Lens Adapter for Canon EF to EOSR with Variable ND Filter and UV Filter for EOS R R5 R6 RP R7 R10 C70
Meike Black Pro-Mist Filter (Optional: 1/8 and 1/4) For Canon and Meik — Meike Global
Canon Lens Mount Adapter Ef Eos R | Canon Eos Rp Lens Adapter | Canon Rf Eos R Adapter - Lens Adapter - Aliexpress
Meike Launches Canon EF to RF Adapter with Drop-in Filters | PetaPixel
Breakthrough Photography Launch a Huge Range of Drop-In Filters for Canon RF Cameras | Architectural Photography Almanac
DROP-IN FILTERS – Breakthrough Filters
Canon Drop-In Circular Polarizing Filter A 3445C001 B&H Photo
These are the First Third-Party Drop-In Filters for Canon's EF-RF Adapter | PetaPixel
Canon Drop-In Filter Mount Adapter EF-EOS R with Variable ND Filter