Check the listing for details. Omega Precision Fine Wire Thermocouples - Copper/Constantan (5 PER PACK). Condition: New – Open box. Listed at 20.00 USD. 8 packs available COCO-002Copper/ConstantanDiameter: 0.002"Length: 12"Insulation: Bare From Omega Website: Fine Gage ThermocouplesOMEGA™ fine wire thermocouples are used whenever fast, accurate temperature measurements are required. The fine wire diameters enable accurate temperature measurements without disturbing the base temperature of the body, in which the installation is made, by keeping heat transfer via the leads to a minimum. Also, the fine junction permits accurate “pin-pointing” of the measured values. They are available in wire sized ranging from 0.001" to 0.032" in diameter. All fine gage thermocouples are made from carefully selected materials. To insure consistent thermoelectric properties, each package contains thermocouples made from matched pairs of wire within the same lot number. When specified, several packages of thermocouples made from the same lot number can be supplied at no extra charge.