Cosina Voigtlander Super Wide Heliar 15mm f/4.5 in Leica M mount. The lens is effectively new. Bought it ~2 months ago from Adorama (can provide purchase slip on request), but after couple of tries realized that it is too wide for me. No issues with the lens. It's yours for $500. Free shipping in CONUS. You pay PayPal fees (+3%) if any.