The BM-3 Compound Student Microscope is a heavy-duty, die-cast monocular microscope designed for regular school and college laboratory use. Compared to the BM-2, BM-3 offers a stronger pressure die-cast body, inclination up to 90°, and improved long-term durability for frequent handling. While both models provide achromatic 10× and 40× objectives and an Abbe condenser (NA 1.25), the BM-3 stands out for its enhanced mechanical stability and classroom robustness, making it better suited for institutions requiring a more rugged student microscope than standard entry-level models.