Continuously variable solenoid with iron core. A scale is fitted to give the value of the inductance. Outer diameter of coil 75mm, thickness 1mm and length 21cm. Solenoid has inductor range 0.15 to 1.4 henry approx. within 20cm length scale. Its resistance 12 ohms approximately. The 1mm copper wire is wound on 20cm long & 75mm dia PVC tube. The henry scale covered from both sides of the solenoid. A henry indicating pointer moves with the center of transparent scale. It works on 250V, 2 Amp.