A cleaved Zuiko Digital EX-25 extension tube with electrical bypass cable.
Here with a Vivitar 7 element 2x Macro-Tele converter* added in-between the camera body and the Zuiko digital 50mm f/2 macro lens. Auto.focus and aperture control is maintained.
* This device is optimized for 50 mm and macro shooting and is of exceptionally high optical quality. The following images are taken with the above setup.