Vivitar 2x Automatic Teleconverter for Olympus OM Film Cameras, doubles the focal length of your telephoto lens so will make a 200mm lens a 400mm focal length, as with all 2x converters you loose two stop of light so will make an f4 lens effectively and f8 speed, cosmetically this converter is used condition with some signs of wear externally on the converter, optically the converter is in good condition and free from fungus and haze.

Teleconverters

S816 (39)