Magnetic Field Pattern Window Description: Easily observe magnetic field pattern lines. Whether placed on top of white paper or projected on the screen, these sealed particles of iron move in a fluid to show the field lines of magnets. Includes a sealed magnetic field window, pair of small ferrite block magnets, a pair of plastic cased bar magnets, and teacher instructions. 22 x 12 x 0.9 cm (9" x 5" x 0.35") BD 3.000 Delivery BD 1.000 الحالة جديد