Uxcell 300mm Focal Length Double Concave Lens, 2 Pack 75mm Diameter 6mm Height Glass Optically Lens, Clear

Double concave lenses are used to disperse light. They can make telescopes, suitable for a variety of applications, including scientific experiments, photography, and optical instruments.

Advantage
Made of quality glass that is durable, scratch resistant, and provides excellent optical performance. Round edges have been polished, it is not easy to hurt your hand when you assemble it.
Designed with a double concave shape that let the light diffuse and produces virtual images.
The lens is accurately measured and has consistent curvature, ensuring consistent performance and results.

Instruction
Place the concave side of the lens facing the object from which you want to disperse the light. Adjust the distance between the object and the lens until the desired level of dispersal is achieved.

NOTE: Double concave lenses are often used in combination with other lenses to create specific optical effects.