It is possible to buy the adapter for...
GIO-SIM Extension with zoom (SIM)
Extension ring in alluminium anodizee of 12 mm
Extension ring in alluminium anodizee of 22mm
Porthole in aluminum anodized with anterior fillet 67 mm for objective macro 105 mm
Porthole in aluminum anodized for objective 60 macros with fillet 67 anterior for slow additional