The distance from the reference surface to the focal point of the C-mount is 17.562 mm, and the focal length of the CS is 12.5 mm.
C-MOUNT 5mm Extension Tube Adapter C-CS Mount Adaptor Spacer Ring For CCTV Lens
C-MOUNT 5mm Extension Tube Adapter C-CS Mount Adaptor Spacer Ring For CCTV L*k*
C-MOUNT 5mm Extension Tube Adapter C-CS Mount Adaptor Spacer Ring For CCTV L*k`
C-MOUNT 5mm Extension Tube Adapter C-CS Mount Adaptor Spacer Ring For CCTV L ZT
C-MOUNT 5mm Extension Tube Adapter C-CS Mount Adaptor Spacer Ring For CCTV L ZC
C-MOUNT 5mm Extension Tube Adapter C-CS Mount Adaptor Spacer Ring For CCTV L GF
