The RB4321CH shares its 140mm temple length and CH naming with the RB4320CH, but the lens opening is smaller at 53mm rather than 58mm - enough of a gap that the two frames aren't interchangeable for replacement lenses. Both are round plastic builds, just scaled differently.

This set is cut to the RB4321CH's 53mm curve, so it seats correctly in that specific frame rather than a close approximation. At €25, it's a low-cost way to replace clouded or scratched lenses while keeping the existing plastic frame in service.

Frequently asked questions

How hard is it to install replacement lenses myself?

Most Redondo frames use a simple press-fit: flex the frame slightly, seat one edge of the 53mm lens into the groove, then work your thumb around the rim until it clicks into place — no tools needed.

What if the lenses I order don't actually fit my frame?

Every pair is matched to a specific model, in this case the 4321, so mis-fits are uncommon, but if the lenses don't seat properly you can return them within 14 days for a full refund, no questions asked.

What's the warranty if a lens pops out or discolors after a few months?

All lenses are independently made and carry a 3-year warranty against manufacturing defects — if a 53mm lens fails to seat correctly or the coating degrades on its own rather than from an impact, we'll replace it free.

Do replacement lenses block UV rays as well as the ones they're replacing?

Every lens we sell, including each option among the over 15 lens colours, including mirrored and polarized options, blocks 100% of UVA and UVB radiation, so changing the color or finish on your 4321 never means sacrificing sun protection.