Internal wiring (positive/negative) each way is constructed of solid coppers. UL94V-0 flame retardant grade, safety factors is greatly enhances. No need for heat shrinked tubing, one-stepped installation of the sheath in place, saving time and effort. Seamlessly compatibility with XT60 male butt joint. Flat welding port with spacers sheath, both to prevent shortcircuit and facilitate welding.