This is an excellent and economical set for introductory ray optics. The laser ray box projects one, three, or five parallel bright beams and is equipped with a momentary switch for safety. A vinyl template with a degree circle and a linear scale forms the optical disk, and the set includes seven clear acrylic optical elements and a mirror with adjustable curvature for investigating refraction, lenses, prisms and mirrors. The bottoms of the acrylic elements are frosted to show the ray paths inside them. Please note: This product emits laser light. Max. output power: <1mW per beam Wavelength: 650nm Class IIIa laser product Contents: * Wall-mount power supply * Laser ray box (1, 3, or 5 rays) * Parallel-sided block * Trapezoidal prism * Right-angle prism * Biconcave lens * Biconvex lens * Semicircular lens (solid) * Semicircular cell * Flexible template—ruler & protractor * Adjustable mirror—plane/concave/convex * Aluminum storage case * Activity guide