Sigma APO 1.4x and 2x teleconverters for Nikon mount. These were purchased a few years ago and were used only once to test their performance against other teleconverters from Kenko and Tamron. Because of their superior performance in the corners of the 35mm frame, I kept these and returned the others, but haven't used them since. Both are in as-new condition in every respect, including all original paperwork and packaging. The 1.4x comes with a soft storage pouch, the 2x with a semi-rigid nylon case. Both can be used with any Nikon F-mount lens or T-ring on a scope, but all functions may not work on some of the newer super-duper all-everything lenses.
New prices are $159 for the 1.4x and $179 for the 2x. My firm prices for these like-new teleconverters include shipping to the lower 48:
1.4x -- $125
2x -- $145
USA buyers only, please.