Circular Coil Mounted on a 254mm x 178mm plastic base.A coil with 94 turns of 1 mm diameter Copper wire is mounted on a plastic base and surrounds a plastic sheet onto which iron fillings or compasses could be placed. Used to observe static magnetic fields generated by a constant flowing current.The base has 2 x 4mm connectors for connection to a Power Supply (12V max.).Please note - Power Supply iron filings and compasses are not included.