(via generic, no labeling on the tubes at all available in all-plastic and with metal mounts electronic contacts produced by DBK Electronics Opteka DG AF Macro Extension Tube C-AF 31mm Opteka DG AF Macro Extension Tube C-AF 21mm Opteka DG AF Macro Extension Tube C-AF 13mm MeiKe C-AF Vario Auto Extension Tube 46 - 68mm

Metal and plastic mount versions available MeiKe C-AF Extension Tube Set 13-21-31mm

compatible with EF as well as EF-S lenses *not compatible with EF-S lenses, but can be modified to fit these *not compatible with EF-S lenses identical to the Danubia tubes