This is a oil immersion brighter darkfield compound microscope condenser (NA 1.36-1.25) for observing unstained transparent specimens in a dark viewing field background. The advanced darkfield microscopy condenser provides much brighter viewing field than the ordinary one. Two images taken from the two darkfield condensers are put here for comparison. It works with a 100X plan darkfield objective AJ100PR. Its mounting size is 37mm in diameter. This oil darkfield condenser fits common size compound / biological microscopes. ?? ??