Marina Aquascaper Plastic Plant, Corkscrew Vallisneria, 20 cm (8 in), safe, non-toxic plastic, they will not affect your aquariums water chemistry. The natural colour finish will not fade and is completely safe for a
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: 50mm length, 25mm face size
Density Cube, Individual cubes for density experiments, Available in eight different materials: acrylic, aluminum, brass, copper, nylon, polypropylene, PVC, and steel, Each material is represented by a 1/2inch, 1inch and 11/2inch cube
Cube, Individual cubes for density experiments, Available in eight different materials: acrylic, aluminum, brass, copper, nylon, polypropylene, PVC, and steel, Each material is represented by a 1/2inch, 1inch and 11/2inch cube
Marina Check Valve prevents water from siphoning out of the aquarium through the air hose and into the air pump in the event of a power failure or when removing filters and other air-driven accessories from the aqu
Cube, Individual cubes for density experiments, Available in eight different materials: acrylic, aluminum, brass, copper, nylon, polypropylene, PVC, and steel, Each material is represented by a 1/2inch, 1inch and 11/2inch cube
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