The M8777 Mil-spec Wire is a single conductor wire made with a copper conductor and silicone insulation. Primarily used for aircraft and missiles, MIL-W-8777 cannot be used in temperatures exceeding 200°C. There are two different cables under MIL-W-8777: MS27110 and MS25471. MS27110 is the standard for MIL-W-8777 wire with an FEP jacket. MS25471 is the standard for MIL-W-8777 wire with a polyester jacket.