Aluminum-to-Copper connector provides a secure connection while preventing aluminum corrosion; Specially formulated corrosion-resistant compound provides cooler connections and increased conductivity; Accepts 1 #12 Al sol. w/ 1 #18 Cu AWG min. and 1 #10; Swept-wing design for comfort; Live-action, square-wire spring; Hexagonal shape for standard nutdriver; No pre-twisting required; UL Listed and CSA Certified; Shell rated for 105 C; Flame-retardant shell