This new EISCO Ray Box is a simple, safe and sturdy source of projected light for many classic optics experiments-best of all, you don't need a completely dark room to conduct optic experiments due to high intensity light used. It produces parallel convergent rays across a plane horizontal surface and the rays are intense enough to be traced in natural light. Built in solid aluminum extrusion casing. Is supplied with a multi slit that produces either a single wide beam or choice of one , three or five pencil thin rays. It is supplies with a power adapter with all international safety certifications which can be plugged into the mains source 100-240V 50/60 Hz, or an external power supply may be used in the lab. It comes with a fixed lens, a slit with multiple sides and an adaptor.