AquaClear 20 Activated Carbon Filter Insert improves water clarity in fresh and saltwater aquariums, for the AquaClear 20 Power Filter, it provides superior adsorption which eliminate odors, discoloration and impu
Equilateral Prism, Material: acrylic, Refractive index close to optical glass, can produce a rainbow from a non-monochromatic light source such as sun light, Perfect for student use, which will not break or chip like glass, is a softer material, Size: 25mm length, 25mm face size