Designed to match the Argus C44 bayonet, this two part adapter works with the Argus Cintagon 50mm/f2.8, 35/f4.5 and 100/f3.5 lenses. It may, or may not, suit other C44 lenses. lens or others made for the C44 camera. The adapter is a bayonet type (to the lens), and a short M2.5mm screw can be fitted to lock the lens in a given position (This does not affect the lens in anyway, it simply stops it rotating in the adapter).
The L39 camera mounting thread on the camera side of this adapter was not intended to connect to Leica cameras (though it will) but chosen to fit commercially avaliable M39 lens adapters like those to Sony E-mount (NEX) or micro four thirds (M43).
The C44 camera has a unique focus ring which engages with the lens barrel to rotate the heliciod. The front of the lens does not turn. To make the lens easier to focus there is a focus ring print ( shown in blue on the photo) - see the associated ring to use with this adapter. shapeways.com/product/ECJNYELAX
Most lenses for the Argus C44 camera were made by Steinhill, while the standard lens on the C44, the kitch looking 50mm f:2.8 Cintagon
(a tessar), made in the USA c1956, is said to be one of the first commercial lenses wholly designed on a computer, the University of Michigan developed MIDAC.
(Note: the 1st version of this adapter was a bit tight & the "window" on the focus ring was slightly too small. This is improved on the current version (2)).