This pair of single-core solar extension cables are specially designed for solar panels to carry high current and have negligible power loss. It comes with waterproof MC4 connectors (male on one lead, female on the other lead) which can be easily connected to similar MC4-type connectors coming with most solar panels, including Photonic Universe solar panels. This cable is suitable for all weather conditions including cold and hot temperatures. 4.0mm cross-section is usually enough for off-grid 12V solar panels and systems up to 160W, or on-grid panels (typical voltage 30-60V) with higher power rating. Cable specifications: Conductor: tinned copper Cross-section: 4.0mm Conductor resistance: 5.09 Ohm/km (20C) Insulation and Jacket: 120C XLPE Working temperature range: -40C to +120C Certification: TUV Outer diameter: 6.1mm