Infinity Corrected Darkfield Microscope Plan Oil Objective 100x with Iris-This is a 100X objective with a variable NA iris for applications such as dark field microscopy. Designed for infinity-corrected microscopes with RMS thread, it is characterized by both chromatic and spherical corrections, offering sharp, focused images. It is designed to be used with immersion oil, and has a spring nosecone to prevent damage to the lens or specimen.