J-Type 24 AWG thermocouple wire with high temperature fiberglass insulation and a solid core.  This wire is good up to about 405 C or 752 F.

• J-Type Thermocouple wire for making thermocouples or extension wires
• Iron / Constantan type-J thermocouple wire with Standard Accuracy (whichever is greater): +/- 2.5C or +/- .75%
• Solid wire, AWG 24 (0.51 mm)
• ANSI color coded fiberglass insulation, white = + (positive), red = - (negative)
• Sold in a 40 yard roll.