Pulley, Single Sheave, Pulleys wheels are made of plastic and mounted securely in an aluminum housing with a hook on both the top and bottom for suspension, Size: 50mm
Ray box, simple, safe and sturdy source of projected light for many classic optics experiments, 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, 100-240V 50/60 Hz