The M39 thread and the rear part of the lens are made of 3D printed plastic. What's in the box: Lens on M39 thread.
@ Steinheil Munich Orthostigmat 4.5/35 mm for Leica Screw Mount US Zone
@ Steinheil Munich Culminar 2.8/8.5 cm coupling Leica screw mount M39 w. caps
#S0420 - With Steinheil Cassar 2.8/45mm
Kodak Retina 35mm Rangefinder, Steinheil Cassar, Prontor-SVS
Montanus Rocca TLR Camera 6 x 6 with Steinheil Cassar 2.8/80 mm Rarity Rare