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
Marina airline tubing is safe and dependable for use with air stones, air-actuated ornaments and air-driven filters. Designed to fit all standard outlets, the tubing will remain supple and retain its shape. Size: 3 m
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
Marina Ultra 4-way air control valve allows you to run up to 4 air-driven products. Each valve has flow adjuster which enables you to regulate air output to each devise. The valve is leak-proof and suitable for fresh