Up for sale is a Panasonic Lumix 20mm f/1.7 pancake lens for use with Micro Four Thirds cameras.  A review of the lens, including full specifications, can be found here:

https://www.dpreview.com/reviews/panasonic-20-1p7-o20

Lovely used condition - functions perfectly, and cosmetically appears barely used.  Please feel free to drop me a line if you have any questions.