The IEC Capacitor boxes are traditional instruments that permit the selection of capacitors in decades (each dial has 10 steps). Accuracy is typically +/- 5%. This 3 dial model provides total of 1.11uF in steps of 0.001uF. Maximum voltage: 400V Dial 1: 0.001 to 0.01uF, Dial 2: 0.01 to 0.1uF, Dial 3: 0.1 to 1.0uF Connection by 4mm spin free terminals with extra terminal for earthing the housing if required.