Unit consists of a platform that is simply attached to the end cheek of the solenoid and a slim blade carrying one single turn of conductor which balances in needle points on the 2 pads on the platform. When current is passed through the solenoid and the single turn, the blade deflects due to the interaction of the magnetic fields. Adding small weights to the blade to restore the balance allows measurement of forces on a conductor in a magnetic field. Solenoid not included.  Made in Australia.