1/4" screw size insulated ring terminals 12-10 GA wire-yellow feature brass sleeves to provide optimum insulation, strain relief and vibration protection.  Nylon insulated terminals are constructed of premium tin plated electrolytic copper  with a brass insulation support sleeve ensuring a stronger vibration resistant termination.  Flared support sleeve eases wire insulation. These terminals provide effective and consistent performance in a variety of industrial, marine, military and aircraft applications.  Manufactured by 3M.  The color reflects wire size per awg code. Temperature range:  -40 - 221 degree F.    UL listed and CSA certified for 600v building wire and 1000v signs and lighting fixtures.