Nylon insulated ring terminals 2 GA-red silver brazed seam that will not open while  crimping .   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.