leica screw to bayonet adapter - brings up the 28/90 frame lines
the one for sale is for lenses with infinity locks - many nikkors & canons
the infinity lock sits up high enough on the lens body to use this
adapter with them
a lens like a screw mount 5cm f3.5 Elmar it sits too close
the full rim covers the reader on the digital m so dirt doesn't enter
the right one is the early full rim type
it has a serial number engraved - when leica introduced the m3 a big selling point
was the ability to use all your existing screw mount lenses on it
you had to send your lenses to Leica to have them fitted with an adapter
both adapters are the same thickness on the flange
leica I believe wanted you to buy their new bayonet lenses
they only required you to send lenses in for a short time , then adapters were sold direct
$45 each adapter plus $4 shipped in a padded envelope in the us
the adapter on the left has sold -