Consisting of a steel frame with lockable, adjustable jaws which will accept 50mm x 20mm ferrite slab magnets or neodymium button magnets. The field strength can be changed by adjusting the distance. Use with the Lascells BIL Coil to determine the flux density in the gap. The unit is supplied complete with 2 ferrite magnets, an eddy current pendulum demonstration and universal accessory bracket.