Double Convex Lens, Highly polished, optically true lens is excellent for physics classroom demonstrations in optics and light refraction, with ground edges, great for physics classrooms, with highest grade, Size: 500mm focal length, Lens measures 3in diameter, 0.1 weight
AquaClear 20 Zeo-Carb Filter Insert effectively eliminates odors, discoloration and impurities in freshwater aquariums, potent chemical duo prevents the buildup of toxic ammonia and nitrite, designed for Power Fil
AquaClear 50 Zeo-Carb Filter Insert effectively eliminates odors, discoloration and impurities in freshwater aquariums, potent chemical duo prevents the buildup of toxic ammonia and nitrite, designed for Power Fil
Desiccator Plate with Holes, made from high quality porcelain, Contains 6 holes, each with a 1.25in diameter, Great for any school or home laboratory, Can be used in a desiccator to remove moisture from specimen and protect against water vapor, 15cm diameter, 0.3in thickness