w/ 500 Series Connectors - Set of 4 ThunderBird BiWire Jumpers employ Direction-Controlled Solid Perfect-Surface Copper+ (PSC+) covered with a Conductive Carbon-loaded extrusion that reduces RF pick-up. Available with AudioQuest’s 500-Series Hanging-Silver plated Purple Copper spades or bananas on either end — simplifying the connection where the speaker cable is attached.