Add the 1.6X Tele-Converter to the front of your zoom lens to shift its focal range in the telephoto direction. The perfect tool when it's inconvenient, dangerous, or even impossible to move as close to the subject as you'd like. There is no appreciable light loss. Note that the Tele-Converter offers partial zooming, vignetting will occur at mid-range through full wide angle.
For greater protection, the face of the unit offers 102mm threads for direct attachment of Schneider 102mm clear UV filters.