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
Filter Paper 125 mm Grade 3 Circles, designed for gravimetric analysis and the preparation of samples for instrumental analysis, High purity, for use in a wide range of critical filtration procedures, Wide range of filter grades and diameters, Ashless 0.007% are very pure filters