nickel-copper alloy wire(Constantan Wire) is a resistance alloy,made up of copper and nickel as the main components. it has a less temp, coeff, of resistance,wider operating temp, range(below 500 ℃ ), good properties on machanical working,hight resistance to corrosion and easy welding. it is able to be used for varrable and strain resistance elements in alternative instruments specification:0.17mm-5.00mm