This is an adapter to convert Contax G lenses to Fujifilm FX mount. Currently, it's difficult to find this product as it's almost out of stock everywhere. I bought it a while ago, intending to use Contax G mount lenses with Fujifilm cameras, but I haven't had many opportunities to use it and don't see myself using it much in the future, so I'm putting it up for sale. If you have Contax G mount lenses and are interested in using them with Fujifilm cameras, how about it?