Optically Worked Double Convex Glass Lens, 75mm Diameter, 300mm Focal Length, Alternate Model Capacity_125mL sized for student-bench stability during

sized for student-bench stability during routine glassware assembly

the cylindrical concave curvature spreading light along a single axis for line-focus and divergence demos

Spring-loaded vinyl jaws open to 2

this low-current 2mA buzzer on a demonstration base sounds whenever current flows through the closed circuit

inches of mercury

Optically Worked Double Convex Glass Lens, 75mm Diameter, 300mm Focal Length, Alternate Model Capacity_125mL sized for student-bench stability duringAlternate model 75mm double convex glass lens at 300mm focal length, the optically worked surfaces and ground polished edges parallel to the main line 300mm focal lens for backup stock use.