22-18 Gauge vinyl insulated ring terminals. Vinyl (PVC) insulation has a flared entry making wire insertion easier. Insulation is molded over a base terminal made from tin plated copper. Temperature rating of 221°F (105°C). Voltage rating of 600 volts. Available ring sizes are: #4, #6, #8, #10, 1/4'', and 5/16''.