Proper adaptation with metal Pentax 6x7 bayonet. Minimal focusing distance 1.2m great for portrait. Firm infinity and bit beyond. Tested: awesome, sharp and contrasty with distinctive bokeh. Remark: soon after 1m lens unscrews, but this is not an issue since tube long enough and re-screwing is smooth & easy.
In fact one can use this feature to come even closer to object. This item is in the category "Cameras & Photo\Lenses & Filters\Lenses".optikka" and is located in this country: SK. This item can be shipped worldwide.