Vivitar Automatic Extension Tube Set – 12mm, 20mm & 36mm

A three-piece extension-tube set for close-up and macro photography. The 12mm, 20mm, and 36mm tubes can be used separately or combined for increased magnification. Because the tubes contain no glass, they maintain the lens’s optical quality while reducing its minimum focusing distance. “Automatic” refers to mechanical aperture operation, not autofocus.