Endoscopy Zoom Coupler C-mount, with the focal length range from 14mm to 32mm, to cover most endoscopic applications. We are offering endoscope objective lens, also known as endoscope coupler, is used to connect an endoscope eyepiece (ocular) with video camera which has a c mount thread around the sensor. This optics objective lens, compatible with many different camera heads from Richard wolf, karl storz, Olympus, smith&nephew, Stryker etc.