This 0.5X focus adjustable C-mount adapter set is compatible with all Parco trinocular stereo and biological microscopes. This C-mount comes with two ring adapters (one 30mm Ø and one 30.5mm Ø) to connect a digital camera to an eyepiece tube, rather than a trinocular port. This adapter set provides an optimized field-of-view for cameras with 1/2" format image sensors.