Potentiometer 4 Wire With Pencil Jockey. Four Constantan Wires 24 Swg Stretched On A Polished Wooden Base Connected In Series With The Help Of Brass Strips Provided With Two 4mm Socket Terminals. A Box Wood Metre Scale Fitted On One Edge Of The Wooden Base Parallel To One Metre Length Of 4 Wires With A Knife Edge Jockey. (per set)