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: 200 mm focal length, Lens measures 2in diameter, 0.2 weight
FLUVAL U2 Poly/Carbon Cartridge, 2 Pack, Cartridge has two sides that combine to provide thorough and effective chemical filtration, the crucial second stage in the filtration process. The polyester filter pad side
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: 200 mm focal length, Lens measures 3in diameter, 0.1 weight