we are offering vaiseshika thumb wheel resistance box. description "vaiseshika" thumb wheel resistance box type 7400-a is a resistance standard substitution instrument. it can be used as a source of resistance of a known accuracy of the order of + 1%. a known value of resistance (ranging from 1 ohm to 1 megohm) can be drawn from the instrument and can be substituted in an electrical circuit or can be used for resistance simulation. for our complete product range please visit our website