16-12 gauge heavy duty nylon-insulated ring terminals, 3/8" stud. Stock is over 50% thicker than a standard ring terminal. Also works with three wire sizes rather than the standard two. This ring terminal is made from 0.050" thick copper, rather than the typical 0.032" thick stock. Provides durability and a longer life. The nylon insulation provides relief from vibration that can cause the wire to fail prematurely. The nylon insulation also prevents incidental metal to metal contact that can cause shorts. Requires two crimps (terminal to wire strands, terminal to insulation of wire). Standard tools perform both crimps. For heavier usage, use a tool that performs both crimps at the same time.